This week brought major news: American ISPs agreed to become copyright enforcers for the music and movie businesses, throttling or disconnecting users after multiple "strikes" against them.

But it wasn't the only big news. Arrests of Anonymous members in Europe, Amazon Appstore issues, and even ocean mud topped our list of the stories that mattered this week.

Major ISPs agree to "six strikes" copyright enforcement plan: American ISPs, including AT&T, Verizon, and Comcast, agreed today on a new scheme to help copyright owners crack down on infringement. Get ready for "copyright alerts."

Anonymous vows revenge after 15 arrested; AntiSec hacks continue: More Anonymous members have been arrested, this time in Italy. The group has promised its usual revenge even as AntiSecurity hacks continue unabated.

Dozens of law professors: PROTECT IP Act is unconstitutional: Ninety law profs from across the political spectrum agree: the PROTECT IP Act, Hollywood's latest anti-piracy proposal, would be an unconstitutional violation of the First Amendment.

Ask Ars: will iTunes Match be used to chase down music pirates?: Plenty of people are wondering if signing up for iTunes Match could reveal the questionable source of their copy of the Village People's "Cruisin." Will Apple use iTunes Match to sort the pirates out from those that actually pay for their music? Apple won't say, but legal experts don't believe they will.

Amazon Appstore problems: why one developer pulled its game: A third-party Android development firm has pulled its popular game from the Amazon Appstore and issued a statement highlighting the problems with Amazon's system.

Astroturf hurts: leadership resigns after GLAAD supports T-Mobile sale: The president and six board members of a major LGBT civil rights organization have resigned amid controversy after the group backed the $39 billion AT&T/T-Mobile merger.

Copyright troll Righthaven now starts paying those it sued: As the Righthaven lawsuit train continues to jump the tracks, the firm has to pay $3,815 to someone it sued last year—and much larger fee requests are on the horizon.

Why ocean mud might matter to your future iPhone: Most gadgets rely on the "rare earths" to function, and China produces 97 percent of the world supply. But a group of Japanese researchers have identified a vast new source: the mud on the ocean floor.

Analysis: Facebook video chatting handy, definitely not "awesome": Facebook over-hyped its announcement of improved chat features, but the ability to chat with groups and make video calls could prove useful to some users.

White House: we "win the future" by making ISPs into copyright cops: The pressure on Internet providers to police 'Net behavior doesn't just come from copyright owners; top government leaders on both sides of the Atlantic agree that ISPs must play a role in online enforcement.