Do you use social networking sites? Is one of them Facebook? Do you log onto your Facebook page from your mobile phone? Is your cell phone provider AT&T? Recently a "glitch" was discovered whereby a woman in Georgia signed on to what she thought was her account, only to see a group of "friends" she'd never heard of. A bit more investigation showed that she was actually accessing someone else's account - and when she told others about it, they tried their own accounts and the same thing happened. All of them were going through the AT&T mobile network.
Now both AT&T and Facebook say they have fixed the problem on their respective ends. AT&T spokespeople say they repaired a "server software glitch" and installed new security measures, and Facebook changed the web site's privacy settings to prevent it from happening again. But this raises serious concerns about the level of protection your information has on a social networking site, and reinforces the idea that you should never put anything on the site that you wouldn't want to become public knowledge - even if you think only your friends will be able to see it.