Boogey men used to scare people out of their privacy, free speech and other rights online. Canonically, these are terrorists, pedophiles, drug dealers, and money launderers but other distasteful people may be used depending on the audience.
Eventually, all of the Four Horsemen of the Infocalypse were trotted out by SOPA/PIPA advocates.
Refers to cybercriminals. The exact meaning changes over time, but generally refers to drug dealers, money launderers, pedophiles, and terrorists. While none of this is new, the term was coinged due to the drastic effects such activity has had on the rights and daily online experiences of regular individuals.
"Thanks to the Four Horsemen of the Infocalypse, the police are now allowed to search my computer whenever they want for whatever reason they want!"