Symantec studied 16 variants of independently developed ransomware over the last two years. The most common malware involves malware that disables a computer and puts up a banner claiming to be from local law enforcement. The criminal is counting on the victim to pay up to avoid the embarrassment of being caught viewing pornography. Most of these scams target pornographic websites and the ransomware locks the victim s computer. Researchers estimate that over $5 million dollars a year is being extorted from victims from these scams.
Source: https://threatpost.com/ransomware-scams-netting-criminals-33000-day-110812/77200/