In the various reactors (consensus/pex/mempool etc), bad behavior should be reported and eventually trickle to the addrbook somehow and call MarkBad() so we know not to dial the peer again. Or not to dial the peer again for a while. Not sure what the addrbook does but we should make sure the behavior is reasonable.

We should discuss the overall strategy of peer ethics before hastily disconnecting/banning nodes (or even being too lenient) because it could cause the network to fragment. Maybe we should err on the side of being lenient (and suffer some spam)?

In any case we should keep a good record of things so when things change (e.g. a peer is marked bad, banned, etc) we know how to debug it. It could be as simple as a log.Info().