That would be a similar question to "how long would I banned from somebody's home if I disgraced myself in it?" The answer no doubt would be the same in either case which is: Until the offender had been forgiven, made a suitable applogy or considered to have been sufficiently reformed or punished.
Why bother anyway, there are plenty of other forums on other boards where one could equally visit, I'm sure that it would be some time before one got banned from each and every one by which time one could always try and make the rounds again especially if a different ISP was used.
