You can't sensibly take the position "if I follow the rules, do X and don't do Y, I'll be ok". Large corporations MAKE the rules. They will try to get away with whatever they can, and how far they succeed depends on how compliant the local legal system is, how corrupt the judges are and whether their opponents can afford to fight. I doubt whether they can restrict the suffix "-book" in most places given how extensive its previous history is, but there may well be jurisdictions where that will work for them.

The steel firm Krupps succeeded in stealing the "krupps.com" domain from a man called Krupps who had registered it for himself before the Internet really mattered; German law let them get away with it. McDonalds tried to stop a McDonald in the Scottish Highlands from continuing to use his own name for his food business; they lost, after costing him a lot of money, but it wasn't for lack of trying.