As long as it is possible to make anonymous accounts it will be hard to blacklist anything but accounts - I think that it simply has to be a sisyphos-work done by the part of the community that find such things interesting. I made a lot of work for steemcleaners/steemabuse in the autumn and it was a constant discussion of resonability and fairness.
The Blacklist simply mean that users (and witnesses) Abit and Pfunk flags the reputation out of a profile.
and to be honest I see no better way than a vigilant and active community. Systemic counter measures can simply get to draconian and can be misused (and if there is something Steemit constantly has to battle with it is misuse).
The problem for most of us is that we may not spot a plagiarist or other abuser and upvote them. If something popped up in my browser to say they had been caught out then I could make my own checks and then take appropriate action of my choice. We need to do all we can to ensure crime doesn't pay and then at least some of them may give up
I think that communication and the ability to find things are one of the greatest challenges on this platform. On the platform it is only possible to write warning etc. in a post and that is not a good way to communicate. Cheetah is already in the commentfield and as there is no privacy on Steemit it is always possible to check all the actions the user has done and all the flags he/she has.
I am still rather dubious about a centralised warning - steemcleaners are not an official channel, just some users that has made their own vigilante organisation (consisting of fine people by the way).