Much of my research is about Internet privacy, which is sometimes entangled with advertising. Friends have asked me how to help them manage advertising and stay safer online. It is handy to collect information in one place. However, the tips that follow are not appropriate for everyone: some ads you might want to keep, some software may be complex to install, some settings may make it difficult to do common tasks online, and if you do not use Firefox the plugins are of no use to you. As is so often the case, different people have different needs and preferences. Please look at this as a list of pointers for things you might investigate, rather than a list of suggestions. Expect to do some reading rather than blindly clicking Submit on a web form.

Why would decent, wholesome, non-criminals want to ensure their web browsing history does not go down on their permanent records? As just one example, a class I took required detailed research of how terrorists might use anthrax, smallpox, or both to attack a super bowl game. Class members pulled details on the stadium air ducts, the rate of the spread of infections, mortality statistics, details on what proportion of attendees travel from out of state or internationally and flight information, and so forth. It was all perfectly legitimate, but imagine what an FBI agent could think of that traffic. Privacy means not needing to explain oneself.

To reduce telemarketing phone calls:

• Add yourself to the do not call list.
• For young men, opt out of military recruiting phone calls (note: the military necessarily tracks the people who opt out.)
• Most political robocalls get phone numbers from the DMV. For a quiet November, leave the (optional!) telephone number field blank when you apply for a driver's license.

To reduce paper advertising:

• Remove yourself from credit card offer mailing lists (note: the only fields required are name and address)
  or call 1-888-5OPT-OUT.
• Register with the DMA to remove yourself from bulk mail lists, which will cost you $1 if you send in the form via physmail.Yes, the DMA suggests using a web form as the "fastest and easiest" approach, better than snail mail. Brave new world.

To block most online advertising from showing up:

• If you use Firefox, you might try Adblock Plus.
• There's also Privoxy, which comes with the OS X bundle for TOR (see below.)

To address data collection for behavioral advertising:

• Well, there is the NAI opt out cookie. Major caveat: in many cases, opt out cookies DO NOT LIMIT DATA COLLECTION.
  The type of ads you see changes, nothing more. There are better ways to protect your privacy if that is what you are looking for.
• Chris Soghoian's TACO is a much better implementation than the NAI cookie, but again, understand what you are actually getting. Installing TACO may also be worth doing as your way to be counted as one more person who does not want to be tracked online.
• Change the default settings in your web browser to refuse 3rd party cookies and clear all cookies on log out (or only accept session cookies.) You may run into issues doing this and details depend on your browser(s).There are a zillion guides for this on the web. Try typing something like "firefox lockdown" into your favorite search engine (bonus tip: with chrome, add the word "browser" to your search.)
• Use multiple browsers, one tuned for privacy while browsing, one not.
• Create multiple accounts on your computer, again one tuned for privacy and another not. To effectively virtualize your web browsing just wipe the entire account.

To block and remove flash cookies:

• Change the permissions on the directory to block write access. This may make your life more difficult.
• Write a quick chron script to regularly remove files, ideally while you are not using flash during the removal.
• Try Adobe's documentation to set the size allocated to 0 KB. Again: this may have annoying side effects.
• Use a browser plugin like flashblocker but note this blocks all flash content.

To reduce being tracked by your IP address or have your location revealed by geoIP:

• TOR is not bet-your-life level protection, but is coming along nicely. Be sure to read about how to use TOR effectively. Like many similar ideas, TOR works best with lots of traffic. If you want to make it harder for oppressive governments to track their citizens, adding innocuous traffic may be a useful form of noise.
• Google and Yahoo! block some TOR connections. Privacy Finder effectively launders TOR traffic to Yahoo! Plus, Privacy Finder is nifty in its own right.You can add Privacy Finder to your list of search engines in at least Firefox and run Privacy Finder searches in the upper right corner just as you would for Google, Wikipedia, etc.

To reduce privacy issues while web surfing from an iPhone:

• Yahoo has an opt out for iPhone browsing; set it from your iPhone.
• Try an app designed with privacy in mind like Privately, which is a tweaked version of Safari.
• As of 3.0, "any Web site can ask Safari for the user’s location, and Safari can provide it by using the location positioning technologies built into the phone (including GPS, among others)" [source: CDT.]
  • As per protocol, websites should request your consent to use location data.
  • If you say yes but later want to revoke permission you must do so for all sites and all apps (camera, maps...) then add back the ones you are willing to allow. To revoke, on your iPhone go to Settings->General->Reset->Reset Location Warnings and click the scary red Reset Warnings button.[Apple's documentation]
• To turn off all location tracking (and also lose a lot of functionality)
use Settings -> General -> Location Services and set the slider to Off.
• Understand that iPhones are inherently insecure against anyone with physical access. Your four character password is cute, but iPhones are highly hackable.

There are many, many other lists like this on the web. EFF has a particularly nice set of suggestions.

If you are interested in these topics, you might also be interested in these groups:
CDT | EFF | Free Press | ALA's Office for Intellectual Freedom | ACLU Privacy & Technology