From a BUSINESSman's perspective, if your Company has a policy specifically against this, and you know about it and don't report it, I think that ALONE would make it "the right thing to do" to expose it to human resources. If not, you yourself could be held partially accountable, as you've pointed out already.
I also think it's MORALLY the right thing to do, and I also believe it WORKS.
But it's far from a unanimous opinion -- I'd put the whole "confront-and-expose" vs. "Little Bo-Peep Approach" at about 35/65, if I had to put a number on it. There are dozens of books and tens of thousands of marriages saved by the more aggressive concepts, but they are still in the minority.
