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39 >Privoxy Frequently Asked Questions</TH
47 HREF="configuration.html"
82 >4.1. How much does <SPAN
85 > slow my browsing down? This
86 has to add extra time to browsing.</A
89 > It should not slow you down any in real terms, and may actually help
90 speed things up since ads, banners and other junk are not being displayed.
91 The actual processing time required by <SPAN
95 itself for each page, is relatively small in the overall scheme of things,
96 and happens very quickly. This is typically more than offset by time saved
97 not downloading and rendering ad images.</P
106 mechanism may cause a perceived slowdown, since the entire page is buffered
107 before displaying. See below.</P
115 >4.2. I noticed considerable
116 delays in page requests compared to the old Junkbuster. What's wrong?</A
119 >Using the default filtering configuration, I noticed considerable delays in
120 page requests compared to the old Junkbuster. Loading pages with large contents
121 seemed to take forever, then suddenly delivering all the content at once.
124 >The whole content must be loaded in order to filter, and nothing is is
125 sent to the browser during this time. The loading time does not really
126 change in real numbers, but the feeling is different, because most
127 browsers are able to start rendering incomplete content, giving the
128 user a feeling of "it works".
131 >To modify the content of a page (i.e. make frames resizeable again, etc.) and
132 not just replace ads, <SPAN
135 > needs to download the
136 entire page first, do its content magic and then send the page to the browser.</P
144 >4.3. What is the "http://p.p/"?</A
150 > sits between your web browser and the Internet, it can be
151 programmed to handle certain pages specially.</P
153 > With recent versions of <SPAN
157 greater), you can get some information about
161 > and change some settings by going to
166 > or, equivalently, <A
167 HREF="http://config.privoxy.org/"
169 >http://config.privoxy.org/</A
171 that p.p is far easier to type but may not work in some configurations. With
172 the name change to <SPAN
175 >, this is changed from
176 the previous http://i.j.b/ and earlier 2.9.x versions).</P
181 > forwarded to a server on the
182 Internet - instead they are handled by a special web server which is built in to
188 > If you are not running <SPAN
196 HREF="http://config.privoxy.org/"
198 >http://config.privoxy.org/</A
200 return a web page telling you you're not running
206 > If you have version 2.0.2, then the equivalent is
207 http://example.com/show-proxy-args (but you get far less information, and
208 you should really consider upgrading to 2.9.14).</P
216 >4.4. Do you still maintain the blocklists?</A
219 > No, not by this name. The format of the blocklists has changed
220 significantly in versions 2.9.x and later. This functionality
224 > file now. See next question ...</P
232 >4.5. How can I submit new ads?</A
241 > This process does not work with earlier versions of <SPAN
256 >4.6. How can I hide my IP address?</A
259 > You cannot hide your IP address with <SPAN
262 > or any other software, since
263 the server needs to know your IP address to send the answers back to you.</P
265 >Fortunately there are many publicly usable anonymous proxies out there, which
266 solve the problem by providing a further level of indirection between you and
267 the web server, shared by many people and thus letting your requests "drown"
268 in white noise of unrelated requests as far as user tracking is concerned.</P
270 >Most of them will, however, log your IP address and make it available to the
271 authorities in case you abuse that anonymity for criminal purposes. In fact
272 you can't even rule out that some of them only exist to *collect* information
273 on (those suspicious) people with a more than average preference for privacy.</P
275 >You can find a list of anonymous public proxies at <A
276 HREF="http://www.multiproxy.org/anon_list.htm"
280 more through Google.</P
291 > guarantee I am anonymous?</A
294 > No. Your chances of remaining anonymous are greatly improved, but unless you
295 are an expert on Internet security it would be safest to assume that
296 everything you do on the Web can be traced back to you.</P
301 > can remove various information about you,
305 > more freedom to decide which sites
306 you can trust, and what details you want to reveal. But it's still possible
307 that web sites can find out who you are. Here's one way this can happen.</P
309 > A few browsers disclose the user's email address in certain situations, such
310 as when transferring a file by FTP. <SPAN
314 does not filter FTP. If you need this feature, or are concerned about the
315 mail handler of your browser disclosing your email address, you might
316 consider products such as <SPAN
321 > Browsers available only as binaries could use non-standard headers to give
322 out any information they can have access to: see the manufacturer's license
323 agreement. It's impossible to anticipate and prevent every breach of privacy
324 that might occur. The professionally paranoid prefer browsers available as
325 source code, because anticipating their behavior is easier. Trust the source,
334 >4.8. Might some things break because header information is
338 > Definitely. More and more sites use HTTP header content to decide what to
339 display and how to display it. There is many ways that this can be handled,
340 so having hard and fast rules, is tricky.</P
345 > in particular is often used in this way to identify
346 the browser, and adjust content accordingly. Changing this now is not
347 recommended, since so many sites do look for this. You may get undesirable
348 results by changing this.</P
350 > For instance, different browsers use different encodings of Russian and Czech
351 characters, certain web servers convert pages on-the-fly according to the
352 User Agent header. Giving a <SPAN
356 operating system or browser manufacturer causes some sites in these languages
357 to be garbled; Surfers to Eastern European sites should change it to
358 something closer. And then some page access counters work by looking at the
362 > header; they may fail or break if unavailable. The
363 weather maps of Intellicast have been blocked by their server when no
367 > or cookie is provided, is another example. There are
368 many, many other ways things can go wrong when trying to fool a web server.</P
370 > If you have problems with a site, you will have to adjust your configuration
371 accordingly. Cookies are probably the most likely adjustment that may
372 be required, but by no means the only one.</P
387 speed up web browsing?</A
390 > No, it does not have this ability at all. You want something like
392 HREF="http://www.squid-cache.org/"
395 > for this. And, yes,
396 before you ask, <SPAN
400 with other kinds of proxies like <SPAN
411 >4.10. What about as a firewall? Can <SPAN
417 > Not in the way you mean, or in the way a true firewall can, or a proxy that
418 has this specific capability. <SPAN
422 protect your privacy, but not really protect you from intrusion attempts.</P
433 > logo that replaces ads is very blocky
434 and ugly looking. Can't a better font be used?</A
437 > This is not a font problem. The logo is an image that is created by
441 > on the fly. So as to not waste
442 memory, the image is rather small. The blockiness comes when the
443 image is scaled to fill a largish area. There is not much to be done
444 about this, other than to use one of the other
455 >, or a URL of your choosing.</P
457 >Given the above problem, we have decided to remove the logo option entirely
466 >4.12. I have large empty spaces now where ads used to be.
470 > It would be easy enough to just eliminate this space altogether, rather than
471 fill it with blank space. But, this would create problems with many pages
472 that use the overall size of the ad to help organize the page layout and
473 position the various components of the page where they were intended to be.
474 It is best left this way.</P
485 > filter Secure (HTTPS) URLs?</A
488 > This is a limitation since HTTPS transactions are encrypted SSL sessions
489 between your browser and the secure site, and are meant to be reliably
493 > and private. This means that all cookies and HTTP
494 header information are also encrypted from the time they leave your browser,
495 to the site, and vice versa. <SPAN
499 try to unencrypt this information, so it just passes through as is.
503 > can still catch images and ads that
504 are embedded in the SSL stream though.</P
519 secure is it? Do I need to take any special precautions?</A
522 > There are no known exploits that might effect
526 >. On Unix-like systems,
530 > can run as a non-privileged
531 user, which is how we recommend it be run. Also, by default
535 > only listens to requests
539 >. The server aspect of
543 > is not itself directly exposed to the
544 Internet in this configuration. If you want to have
548 > serve as a LAN proxy, this will have to
549 be opened up to allow for LAN requests. In this case, we'd recommend
550 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
554 > config file. All LAN hosts can then use
555 this as their proxy address in the browser proxy configuration. In this way,
559 > will not listen on any external ports.
560 Of course, a firewall is always good too. Better safe than sorry.</P
568 >4.15. How can I temporarily disable <SPAN
574 > The easiest way is to access <SPAN
578 browser by using the special URL: <A
583 and select "Toggle Privoxy on or off" from that page. </P
591 >4.16. Where can I find more information about <SPAN
595 and related issues?</A
598 > Other references and sites of interest to <SPAN
612 HREF="http://www.privoxy.org/"
614 >http://www.privoxy.org/</A
635 HREF="http://sourceforge.net/projects/ijbswa"
637 >http://sourceforge.net/projects/ijbswa</A
639 the Project Page for <SPAN
644 HREF="http://sourceforge.net"
670 > from your browser. Alternately,
672 HREF="http://config.privoxy.org"
674 >http://config.privoxy.org</A
676 may work in some situations where the first does not.
696 HREF="javascript:w=Math.floor(screen.width/2);h=Math.floor(screen.height*0.9);void(window.open('http://www.privoxy.org/actions','Feedback','screenx='+w+',width='+w+',height='+h+',scrollbars=yes,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());"
700 >"Privoxy - Submit Filter Feedback"</SPAN
721 HREF="http://www.junkbusters.com/ht/en/cookies.html"
723 >http://www.junkbusters.com/ht/en/cookies.html</A
740 HREF="http://www.waldherr.org/junkbuster/"
742 >http://www.waldherr.org/junkbuster/</A
759 HREF="http://privacy.net/analyze/"
761 >http://privacy.net/analyze/</A
778 HREF="http://www.squid-cache.org/"
780 >http://www.squid-cache.org/</A
806 HREF="configuration.html"