Money Laundering is a serious risk banks face, you only need to look at HSBC's recent debacles to see why.
It's not a risk, it's a business opportunity. At least it was for HSBC http://www.bbc.co.uk/news/business-18866018 . Joe Schmo from small Town, MN would have been a felon by now for doing the same with $10K. The fact that HSBC, other banks (NY Mellon Bank iirc too) and their execs got away with a "cost of doing business fine" shows what's wrong with the system