is there a way on proon for someone to find out how many people are ignoring them, or possibly even find out *who* is ignoring them ?
No and no. For pretty obvious reasons.
point out via private message to someone who's being very annoying that a fair number of people are now ignoring them and thus their time spent posting verbal garbage is partly being wasted
Just ignore them, with the warm knowledge that they are wasting their time (as far as you are concerned).
SD