CSF does a good job blocking IP's that fail to authenticate access to my VPS. I look up these IP addresses, and often they belong to smaller hosting websites. Would reporting this activity to the block IP owner do any good or just waste my time? They want to stick it to me, so I want to stick it right back. And I only host my own sites. Thanks.
Yes it would help, the host will get involved and email the server owner, in turn causing them to stop. The real question is, how many different IPs are we talking about and how many hosts will you have to email?
If the person trying to hack is hosted by a reputable host, I think then reporting it may do some limited good, because the attack site will be forced off that host most likely. However, the attacker will just find a new host.
Although, you've just given me a little business idea... just contemplating whether it be worth trying it...