John can be sued for the website & the domain name ?

Actually no, he can't. If the domain is available and he registers it it will belong to him. The if he clearly states that it is a tribute to the man say Saga, the he is covered. But don't just register the name and not do anything with it, because he could wind up in a cyber squatting case then if hasbro decided to do something with it. But without checking, I would doubt that hasbro would be free, maybe the org would.