According to Morton, ICE's seizure of eight domain names prompted 80 other sites selling counterfeit goods to shut down on their own.
"I've never seen that kind of deterrence come from a single law enforcement action before," Morton said at the State of the Net conference in Washington on Tuesday.
The firms also wrote in support of the Combating Online Infringement and Counterfeits Act (COICA), which stalled in the Senate during last Congress after passing the Judiciary Committee and will likely be introduced again this session by Sens. Patrick LeahyPatrick LeahyThe Hill's 12:30 Report The Hill's 12:30 Report Passing US-Canada preclearance would improve security and economy MORE (D-Vt.) and Orrin HatchOrrin HatchTax reform: Starting place for jobs, growth Overnight Finance: Senate Dems dig in as shutdown looms | Trump taps fast-food exec for Labor chief | Portland's new CEO tax Mnuchin, Price meet with GOP senators MORE (R-Utah).
The bill would make it easier for the Justice Department to shut down websites providing pirated materials by shutting down the domain after receiving a preliminary court order. The bill has broad support from the U.S. Chamber of Commerce as well as the clothing, entertainment and software industries.
However, critics including the Electronic Frontier Foundation, have argued the bill amounts to online censorship and would infringe on Americans' free speech rights.
Sen. Ron WydenRon WydenSenate sends annual defense bill to Obama's desk Senate fight over miners' heathcare boils over Budowsky: Did Putin elect Trump? MORE (D-Ore.) has been COICA's most vocal opponent on the Hill, calling its approach too heavy-handed and vowing to put a formal hold on the bill to prevent a floor vote. Two of his home state's largest firms, Nike and Adidas, are both supporters of the legislation.