It really depends on the individual case for me. I'll delete it if its of low content, and if its particularly a problem I'll message the users involved. If they ignore that or is unbearable I might ignore it so that a higher up member of staff can take a look at it, and decide whether its ban worthy or not. I know this doesn't answer your question, but I guess you sort of see my take on things when I receive reports like this. I get a lot of these types of reports!