can this happen with hosting servers? if any one site gets banned from a web hosting server ,though he is a spam for incidence! are there any chance for other innocent adsense users to get disabled as all of em have hosted sites in the same server
adsense do not ban accounts hosted in such hosting server. But google blacklists the sites in the server.
I do not think that other users will automatically be banned because one got banned. Google makes the difference between websites, however, web hosting is shared hosting and some hosting shares the same IP address. If you are sharing the same IP with hundreds of other sites, I think it is lightly more risky.