We had our own SOPA style war over here in the UK. Lasted over 15 years.
Things didn't go so far as dozens of websites being hacked in a tit for tat, but it was damn nasty: http://en.wikipedia.org/wiki/ACS:Law.
This guy was just sending out speculative letters to individuals, not businesses, but members of the public, just on a whim.

He was demanding lists of ISP's customers and their browsing habits, picking randomly and sending letters.

IMO the media industry shouldn't have been given carte blanche rights to take the law into their own hands, often riding roughshod over anyone who happened to stumble upon a file sharing site. They were supposed to be regulated, but a lot of their actions were often overlooked once a backhander had been paid to th regulators.