Yes - I have received a number of these requests. I answered one. Was most defiantly not American (I could tell by how he wrote). Within a couple of days he was planning our marriage. I blocked him right away and made sure not to accept any other requests of this sort. One thing more, he was adament about having me log into yahoo messenger. I didn't have an account and didn't want to create one. Not sure why this was so important, maybe it's a way to get to other personal info. Don't know.
Block him right away.