I can see the ban on Stack Overflow is on a lower level, such as, if one got banned, his IP address too will be restricted such that no one can post from it again!
I think it will affect many Stack Overflow members since many of the companies use a shared IP address for its employees. We often ask or answer questions here during our worktime. When any member of the company using a Stack Overflow account got banned, then every one else also got restricted from asking or answering questions.
I think it will affect productivity of the entire site and its members interest in contributing here too.
So I suggest to impose a lower level ban when at least
n profiles got banned from a particular IP address. (