Guys need your advice. Kind of concerned with what I got in the mail.

Good news is, got my card and everything, so happy about that.

Bad news, Got a letter in the mail same day I got my card saying

"Thank you for opening your new credit card account with us. We reviewed the information you provided when you opened your account and realized that we need to confirm your Social Security Number."

There's a form (That looks suspicious by the way) enclosed and the letter states

"Please understand that if we do not receive the requested documentation by April 29, 2013 we will close your account."

I called chase, they said that's strange and they would never verify personal info through the mail such as SSN...

Any ideas or similar situations guys? :S