I'm no professional, but I've been in a lot of trouble. I can say with 99% certainty that letter is unrelated if you do a google search on victim programs (which I have put people into hehe) it generally means you or a member of your household at some point file a fraud complaint or your bank has problems and the feds are investigating to protect you, but like someone else here said, if your seeds arrive simply hand them off to a friend for a while or toss them, come back to the idea of growing when you know what the letter is truely about.
P.S. Got 25 seeds from attitude not long ago, and seeds from Nirvana only 1 weeks before that and I don't think seeds are even detectable especially since they are only a couple grams including the packaging and shipped well hidden.