I got this from a friend of mine (thanks NK) which is a scam warning coming from Canada Revenue Agency (CRA). At first I thought it was a joke SO I took the usual precautions. I opened up IE and by manualy typing in the webpage, I went to see Canada Revenue Agency's website and low and behold the information is indeed legit.

The warning is from last summer, but with tax time around the corner, I'm sure this is making it's rounds again.
Here is what the fake scam letter looks like.

Anytime someone asks for credit card, passport, bank numbers, you should be suspicious! Did you call them? Maybe it's legit. Did they call you? That's when you should be asking some hard questions and become VERY suspicious! Maybe even doing a "*69" to get the phone number and then calling the authorities.
By this blog, I don't want to scare people, only inform about what's going on. This has been posted on the CRA's website, so I highly doubt it's a hoax and is something to take seriously.
What do you do if you get one of these letters? I would seriously give CRA a call! One, to confirm everything's ok (you called them right, so you should be safe) and two to let them know you've been targetted and maybe it'll give them amunition to persue the guilty.