" He can't block him or he doesn't want to"

It is my understanding that blocking is a last resort for several reasons. One- it often requires blocking a range of IP addresses, which 'could' inconvenience an innocent party. Two- it is relatively easy to get around IP blocking if one is determined.(never mind how...if you don't know, you don't need to know) Three- It is sad to NEED to resort to that. It is always better to convince the 'offender' to repent and settle into a more congenial manner.

   In this case, it is hard to find any particular sin or crime to justify banning....being terminally tedious is sort of a different matter. Don't you have relatives who don't 'quite' merit being disowned by the family?