This guy didn't just buy the haunted house that previously had signs directing serial killers to where the victims are, he also reinstalled the signs and opened it back up to the public knowing that the serial killers were still around and reading the signs.

I mean, it's a bit absurd to compare copyright infringement to murder, but that's where your analogy started. He didn't just by the domain and do something innocent, he actually started running the software that helps people pirate things strongly suspecting that pirates would use it to help them pirate things... and then when he observed that was reality he (smartly IMO) shut it down.