Aye - the queries are not dangerous per say as it's just a matter of going to the specific tables Brogan notes and removing the rows in question.
But you have a bigger problem (maybe a moral problem) at hand here if you have people considered to be in authority at your website that are going behind people's backs and making fun of other members. That is one thing I do not tolerate for a second at our site. At our site, if you can't say something to someone in person, then don't be saying it behind their backs either. Evidently, if you feel ashamed that you must remove certain reports then it's obvious these "moderators" don't have the 1) cojones to run a site properly and 2) wouldn't dare say something to these people in person. Like I said, you have a bigger problem than mere reports.
I've gone slightly off topic, but you can find more support for this kind of problem at AdminExtra and other similar sites.