What the Heck!!!!

I received a mail today and I was shock to see a plastic container like a ziplock from USPS,it was really funny coz all I got is the back part of the envelope where u put the address.. I just wonder who did this and why they still sent it to me knowing it has nothing to read except for the senders name and mine.This is really bogus and alarming coz there was nothing inside except for the christmas card from Rose. I just wonder if anyone here has the same dillema as I have now,I guess we have to be very extra careful now a days of what we are going to put inside our christmas card when we send it to our love ones. I just feel sad coz I didn't really expect that it will happen to me and knowing this is USA..I hope nobody has experienced what I am having now...it is pissing me off. This is what I received and isn't it ironic when the post office plastic envelope logo is WE CARE,if they really do,they should not have open it in a first place or if they did,why they didn't put it together and send the whole thing to me since the plastic enevelope is big enough.