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38 >Privoxy Frequently Asked Questions</TH
46 HREF="configuration.html"
81 >4.1. How much does <SPAN
84 > slow my browsing down? This
85 has to add extra time to browsing.</A
88 > It should not slow you down any in real terms, and may actually help
89 speed things up since ads, banners and other junk are not being displayed.
90 The actual processing time required by <SPAN
94 itself for each page, is relatively small in the overall scheme of things,
95 and happens very quickly. This is typically more than offset by time saved
96 not downloading and rendering ad images.</P
105 mechanism may cause a perceived slowdown, since the entire page is buffered
106 before displaying. See below.</P
114 >4.2. I noticed considerable
115 delays in page requests compared to the old Junkbuster. What's wrong?</A
118 >Using the default filtering configuration, I noticed considerable delays in
119 page requests compared to the old Junkbuster. Loading pages with large contents
120 seemed to take forever, then suddenly delivering all the content at once.
123 >The whole content must be loaded in order to filter, and nothing is is
124 sent to the browser during this time. The loading time does not really
125 change in real numbers, but the feeling is different, because most
126 browsers are able to start rendering incomplete content, giving the
127 user a feeling of "it works".
130 >To modify the content of a page (i.e. make frames resizeable again, etc.) and
131 not just replace ads, <SPAN
134 > needs to download the
135 entire page first, do its content magic and then send the page to the browser.</P
143 >4.3. What is the "http://p.p/"?</A
149 > sits between your web browser and the Internet, it can be
150 programmed to handle certain pages specially.</P
152 >With recent versions of <SPAN
155 > (version 2.9.x), you can get some
156 information about <SPAN
159 > and change some settings by going to
164 > or, equivalently, <A
165 HREF="http://config.privoxy.org/"
167 >http://config.privoxy.org/</A
169 (Note that p.p is far easier to type but may not work in some
170 configurations. With the name change to <SPAN
174 this is changed from the previous http://i.j.b/ or earlier 2.9.x versions).</P
179 > forwarded to a server on the Internet
180 - instead they are handled by a special web server which is built in to
186 >If you are not running <SPAN
194 HREF="http://config.privoxy.org/"
196 >http://config.privoxy.org/</A
198 return a web page telling you you're not running
204 >If you have version 2.0.2, then the equivalent is
205 http://example.com/show-proxy-args (but you get far less information, and you
206 should really consider upgrading to 2.9.13).</P
214 >4.4. Do you still maintain the blocklists?</A
217 > No. The format of the blocklists has changed significantly in versions
218 2.9.x and later. Once we have released the new stable
219 version, v3.0, there will again be blocklists that you can update
228 >4.5. How can I submit new ads?</A
231 > As of now, please discontinue to submit new ad blocking infos. Once we
232 have released the new version, there will again be a form on the website,
233 which you can use to contribute new ads.</P
241 >4.6. How can I hide my IP address?</A
244 > You cannot hide your IP address with <SPAN
247 > or any other software, since
248 the server needs to know your IP address to send the answer to you.</P
250 >Fortunately there are many publicly usable anonymous proxies out there, which
251 solve the problem by providing a further level of indirection between you and
252 the web server, shared by many people and thus letting your requests "drown"
253 in white noise of unrelated requests as far as user tracking is concerned.</P
255 >Most of them will, however, log your IP address and make it available to the
256 authorities in case you abuse that anonymity for criminal purposes. In fact
257 you can't even rule out that some of them only exist to *collect* information
258 on (those suspicious) people with a more than average preference for privacy.</P
260 >You can find a list of anonymous public proxies at <A
261 HREF="http://www.multiproxy.org/anon_list.htm"
265 more through Google.</P
276 > guarantee I am anonymous?</A
279 > No. Your chances of remaining anonymous are greatly improved, but unless you
280 are an expert on Internet security it would be safest to assume that
281 everything you do on the Web can be traced back to you.</P
286 > can remove various information about you,
290 > more freedom to decide which sites
291 you can trust, and what details you want to reveal. But it's still possible
292 that web sites can find out who you are. Here's one way this can happen.</P
294 > A few browsers disclose the user's email address in certain situations, such
295 as when transferring a file by FTP. <SPAN
299 does not filter FTP. If you need this feature, or are concerned about the
300 mail handler of your browser disclosing your email address, you might
301 consider products such as <SPAN
306 > Browsers available only as binaries could use non-standard headers to give
307 out any information they can have access to: see the manufacturer's license
308 agreement. It's impossible to anticipate and prevent every breach of privacy
309 that might occur. The professionally paranoid prefer browsers available as
310 source code, because anticipating their behavior is easier. Trust the source,
319 >4.8. Might some things break because header information is
323 > Definitely. More and more sites use HTTP header content to decide what to
324 display and how to display it. There is many ways that this can be handled,
325 so having hard and fast rules, is tricky.</P
330 > in particular is often used in this way to identify
331 the browser, and adjust content accordingly. Changing this now is not
332 recommended, since so many sites do look for this. You may get undesirable
333 results by changing this.</P
335 > For instance, different browsers use different encodings of Russian and Czech
336 characters, certain web servers convert pages on-the-fly according to the
337 User Agent header. Giving a <SPAN
341 operating system or browser manufacturer causes some sites in these languages
342 to be garbled; Surfers to Eastern European sites should change it to
343 something closer. And then some page access counters work by looking at the
347 > header; they may fail or break if unavailable. The
348 weather maps of Intellicast have been blocked by their server when no
352 > or cookie is provided, is another example. There are
353 many, many other ways things can go wrong when trying to fool a web server.</P
355 > If you have problems with a site, you will have to adjust your configuration
356 accordingly. Cookies are probably the most likely adjustment that may
357 be required, but by no means the only one.</P
372 speed up web browsing?</A
375 > No, it does not have this ability at all. You want something like
377 HREF="http://www.squid-cache.org/"
380 > for this. And, yes,
381 before you ask, <SPAN
385 with other kinds of proxies like <SPAN
396 >4.10. What about as a firewall? Can <SPAN
402 > Not in the way you mean, or in the way a true firewall can, or a proxy that
403 has this specific capability. <SPAN
407 protect your privacy, but not really protect you from intrusion attempts.</P
418 > logo that replaces ads is very blocky
419 and ugly looking. Can't a better font be used?</A
422 > This is not a font problem. The logo is an image that is created by
426 > on the fly. So as to not waste
427 memory, the image is rather small. The blockiness comes when the
428 image is scaled to fill a largish area. There is not much to be done
429 about this, other than to use one of the other
440 >, or a URL of your choosing.</P
442 >Given the above problem, we have decided to remove the logo option entirely
451 >4.12. I have large empty spaces now where ads used to be.
455 > It would be easy enough to just eliminate this space altogether, rather than
456 fill it with blank space. But, this would create problems with many pages
457 that use the overall size of the ad to help organize the page layout and
458 position the various components of the page where they were intended to be.
459 It is best left this way.</P
470 > filter Secure (HTTPS) URLs?</A
473 > This is a limitation since HTTPS transactions are encrypted SSL sessions
474 between your browser and the secure site, and are meant to be reliably
478 > and private. This means that all cookies and HTTP
479 header information are also encrypted from the time they leave your browser,
480 to the site, and vice versa. <SPAN
484 try to unencrypt this information, so it just passes through as is.
488 > can still catch images and ads that
489 are embedded in the SSL stream though.</P
504 secure is it? Do I need to take any special precautions?</A
507 > There are no known exploits that might effect
511 >. On Unix-like systems,
515 > can run as a non-privileged
516 user, which is how we recommend it be run. Also, by default
520 > only listens to requests
524 >. The server aspect of
528 > is not itself directly exposed to the
529 Internet in this configuration. If you want to have
533 > serve as a LAN proxy, this will have to
534 be opened up to allow for LAN requests. In this case, we'd recommend
535 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
539 > config file. All LAN hosts can then use
540 this as their proxy address in the browser proxy configuration. In this way,
544 > will not listen on any external ports.
545 Of course, a firewall is always good too. Better safe than sorry.</P
553 >4.15. How can I temporarily disable <SPAN
559 > The easiest way is to access <SPAN
563 browser by using the special URL: <A
568 and select "Toggle Privoxy on or off" from that page. </P
576 >4.16. Where can I find more information about <SPAN
580 and related issues?</A
583 > Other references and sites of interest to <SPAN
597 HREF="http://www.privoxy.org/"
599 >http://www.privoxy.org/</A
620 HREF="http://sourceforge.net/projects/ijbswa"
622 >http://sourceforge.net/projects/ijbswa</A
624 the Project Page for <SPAN
629 HREF="http://sourceforge.net"
655 > from your browser. Alternately,
657 HREF="http://config.privoxy.org"
659 >http://config.privoxy.org</A
661 may work in some situations where the first does not.
677 HREF="http://www.junkbusters.com/ht/en/cookies.html"
679 >http://www.junkbusters.com/ht/en/cookies.html</A
696 HREF="http://www.waldherr.org/junkbuster/"
698 >http://www.waldherr.org/junkbuster/</A
715 HREF="http://privacy.net/analyze/"
717 >http://privacy.net/analyze/</A
734 HREF="http://www.squid-cache.org/"
736 >http://www.squid-cache.org/</A
762 HREF="configuration.html"