These days lots of IP addresses are shared, so we could undeservingly ban someone who had a common IP address. Combine that with people using multiple platforms and it makes the job quite tricky, especially for someone as IT illiterate as myself.
If we banned all the annoying little tits on NSC, it would be a very lonely place though.
We could make the ban permanent, but he will then rejoin under yet another name, and it takes a while to work out who he is!