[roasm]

A valid reason to give to the victim is that you're not just protecting her but any other current or potential victims (using nicer language than this). That will help her feel good about coming forth with the information; she's not causing trouble for the company but actually saving someone else from harassment.

[anotherevan]

Yes, I really liked patio11's likening it to embezzlement, being a crime against the company (although in the case of harassment, it is a crime against both the company and the individual recipients).