Given that some courts have found that people can be charged for violating the terms of service of a particular site, it's important to keep track of what the terms of service are so you don't inadvertently violate them.

(Incidentally, some other courts are finding that violating terms-of-service policies are not worth criminal charges.)

But what do you do if a site changes its policies, as Twitter has been known to do?

Now there's help. A new site, TOSBack, sponsored by the Electronic Frontier Foundation, tracks 44 terms-of-service policies, and notes when and what changes are made.

Sites that TOSBack tracks are Amazon, Apple, Automattic, Blizzard, Craigslist, Data.gov, DoubleClick, EBay, Electronic Frontier Foundation, Facebook, Flickr, GoDaddy, Google, MySpace, Organizing For America, Recovery.gov, Twitter, Whitehouse.gov, Yahoo!, and YouTube.

One example of an upcoming change will be "verified accounts" in Twitter. After a number of cases of Twitter spoof impersonation, ranging from Idaho Governor C.L. "Butch" Otter to St. Louis Cardinals manager Tony La Russa (who is suing the company, though it denies it settled the case), Twitter says it plans to verify the accounts of "public officials, public agencies, famous artists, athletes, and other well known individuals at risk of impersonation."

"Initially, verification will not be tested with businesses. However, we do see an opportunity in that arena so we'll keep you posted when we have something to share," the company added. Whether that means someone won't be able to sign up for the Twitter ID "McDonalds" even if that's their name is not clear.