In a way, the scam/spam police do exist, in the form of steemcleaners, cheetah, etc. They take actions to negate rewards or to spread the word, but it sounds like you may be wanting someone with some kind of legal authority or some kind of punishment beyond the community's own moderation?

Expelling someone from the platform (as in Steemit) is an intriguing idea. The problem is, however, while a user may abandon an account because a number of folks knock down their reputation, making it virtually impossible for their articles to be seen, that doesn't seem to apply to wallet transactions.

We've been told that accounts are sacrosanct. In other words, they won't be touched by Steemit or anyone else, so I'm not sure what other recourse there might be.