Sadly, It's Me

The other day I got an "is it really you?" message from a long-lost friend on Facebook. Indeed it was really me; we enjoyed a civil exchange pleasantries and that was the end of it. But since then I have started to get bogus "is it really you?" message from the vendors of, oh, who knows, pit vipers or unlicensed Kalashnikovs. Is the timing sheer coincidence, or is the some way the pestiferous ones have learned how to harness the legit messages for their legions of crap?