Then they ask for the excess, sent accidentally, to be returned to them. After you do this, their check bounces, the money vanishes from your account, and they disappear with the money you sent.

Wow, that’s some crazy s..t. About a year ago I had a similar incident. Not with roommate, but with scam. I had a phone call, and this guy said he was from IRS. First I didn’t think it was a scam, he was asking some basic questions. More he asked, more I became suspicious. At the end he wanted to ask me for my social, and I never share these type of sensitive info over the phone. He became angry and told me he issued a warrant against me and in a few hours the police comes to pick me up. I hung up the phone and saved his phone#. I went to the police to report it, but they told me they couldn’t do anything about it, they said it happened to them as well and this guy is probably somewhere from India where most of these scams originate.