Zeroxal might have used botnet services or be avoiding paying tax, if you think that is the case then you should have reported it to the Finnish police with any accompanying evidence. That way, a person who is in the correct position of legal authority could have run a sting operation which was signed off by a judge. Amateurs trying to run extortion schemes would likely just become an accomplice to the original crime, regardless of your intentions. Trying to act too clever can be your undoing.