I hope it was an error with my account, but I have a feeling there is more going on. What is really creepy is that Cox OWNS Equifax. They have been in a "partnership" since 2002, and pre-check your credit b4 they send out all those mailers. Interesting press release on this at:
http://www.prnewswire.com/cgi-bin/stories.pl?ACCT=104&STORY=/www/story/05-03-2006/0004353960&EDATE=
So if you get junk mail from Cox, it's an indication that they already know your credit is good. So why on earth would they need a three-month security deposit, and your SSN? I would never have remembered giving them a deposit if they hadn't asked for my SSN--it went against everything I've read, raising a red flag. Now this one company has my credit report, my internet, tv, and phone records.
An interesting aside--I asked a neighbor (who had signed up for cable phone around the same time) if she remembered the required security deposit. She couldn't remember, but thought it rang a bell. Here's the rub--she didn't save bills, so she has no record of the deposit if it was prorated over her first three bills. She also doesn't get paper bank statements, and her online banking transactions only go back 6 months. So after a year has passed, most people would have no record of having left a security deposit a year earlier.
I got my money back, but I'm just posting this last note as food for thought for anyone who's thinking of signing up.