# How Do Workplace Web Filters, Like Websense, Work? **URL:** \ **Category:** Factual Questions\ **Created:** [December 22, 2004, 1:34pm UTC](https://boards.straightdope.com/t/how-do-workplace-web-filters-like-websense-work/281146 "2004-12-22T13:34:18Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![HeyHomie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heyhomie/32/207_2.png) [@HeyHomie](https://boards.straightdope.com/u/HeyHomie)\ **Post date:** [December 22, 2004, 1:34pm UTC](https://boards.straightdope.com/t/how-do-workplace-web-filters-like-websense-work/281146/1 "2004-12-22T13:34:18Z")
No, I’m not asking how to bypass them. Anyway, my workplace uses websense to filter “objectionable” web content from our workplace computers. The IT department’s definition of “objectionable” is quite different from mine, but that’s another thread. Websense blocks certain pages based on categories. For example, I can’t check my lottery numbers on [illinoislottery.com](http://illinoislottery.com) because I get a blank screen with the message “The category ‘Gambling’ is blocked by Websense.” Ditto for [msn.com](http://msn.com)’s relationship advice column (“Dating and Personals”); fantasy football reports (“Games”); my PS2 games review site (“Games” again); the website for the movie _Saw_ (“Tasteless”); and, strangely enough, a militant pro-Zionist (or anti-Zionist; I was never able to find out) website that I stumbled on to while searching for information about Chanukkah (“Militancy and Extremism”). How does a web filter know a page’s content? Do ISP’s put some kind of cookie or something on each page, to let the filters know what’s up? Like, some code that says “This page is about gambling.”? Or do they look for keywords? Although I’d have to say that if it were keywords my workplace web filter would definitely block the SDMB, as the word “Dope” in the title would flag it for “Drugs.” Anyone know the scoop? ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [December 22, 2004, 1:41pm UTC](https://boards.straightdope.com/t/how-do-workplace-web-filters-like-websense-work/281146/2 "2004-12-22T13:41:21Z")
Keyword and content filtering is the most basic step. Many filtering packages also have actual humans who surf around looking for stuff to add to the block list. Sounds like an interesting job. ---
**Author:** ![BwanaBob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bwanabob/32/2985_2.png) [@BwanaBob](https://boards.straightdope.com/u/BwanaBob)\ **Post date:** [December 22, 2004, 1:51pm UTC](https://boards.straightdope.com/t/how-do-workplace-web-filters-like-websense-work/281146/3 "2004-12-22T13:51:01Z")
Look at the source HTML of a page and you’ll most likely find a METATAG section near the top. Those tags are “topical” to help search engines (or mislead them). They can be used for “filtering” purposes. At my job, sports and gambling sites are filtered out. ---
**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\ **Post date:** [December 22, 2004, 1:57pm UTC](https://boards.straightdope.com/t/how-do-workplace-web-filters-like-websense-work/281146/4 "2004-12-22T13:57:21Z")
> [@](#): > > …Keyword and content filtering is the most basic step. Many filtering packages also have actual humans who surf around looking for stuff to add to the block list… - - - According to various stories I’ve seen on tech sites, keyword filtering is almost always the _only_ step. The companies that create this software want you to think that all of it has been verified by a person, but it would seem that only sites that are allowed through and that get complained about ever get viewed by a real person there. …The last time I saw a story on the matter, it noted that (when they checked) the web-filtering software that many US public schools were using would not allow you to visit Dick Cheney’s website or visit the National Institute of Health website at all, because it frequently contained keywords concerning reproductive organs and sex. ~ ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [December 22, 2004, 3:36pm UTC](https://boards.straightdope.com/t/how-do-workplace-web-filters-like-websense-work/281146/5 "2004-12-22T15:36:21Z")
> [@DougC](#): > > The last time I saw a story on the matter, it noted that (when they checked) the web-filtering software that many US public schools were using would not allow you to visit Dick Cheney’s website or visit the National Institute of Health website at all, because it frequently contained keywords concerning reproductive organs and sex. > ~ You mean like, “Dick?” 🙂 I do know of at least one filtering company that had a whitelist process. If something was, IYHO, inappropriately blocked, you could press a button and an actual human would review it and remove it from the block list if it was innocent. ---
**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\ **Post date:** [December 22, 2004, 3:50pm UTC](https://boards.straightdope.com/t/how-do-workplace-web-filters-like-websense-work/281146/6 "2004-12-22T15:50:41Z")
They are not very clever at all. They are just a database of banned sites in various categories. An employer can choose which categories to block. When I was doing security work I convinced management to unblock things like banking sites because it is quicker for staff to do internat banking than phone banking. The SDMB usually comes up as entertainment. ---
**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\ **Post date:** [December 22, 2004, 3:54pm UTC](https://boards.straightdope.com/t/how-do-workplace-web-filters-like-websense-work/281146/7 "2004-12-22T15:54:10Z")
As far as I know software suppliers update these lists manually.