Jim,
On the SHAPE board we would require that each person would let someone in the group know their proper name. One reason is that we also kept their email address on file. We had several posters who used a nickname on a regular basis, and theze are not the ones I had trouble with.
Any suspect people I could compare IP numbers. I could then block or warn any offenders. All of us in SHAPE know who Day-O is. I think we all a bit surprised.
GP