I'd hold off a bit on the wailing and gnashing of teeth. Just last year, Resident Bush signed 18 USC 2257, a similar law specifying all sorts of mandatory recordkeeping for websites. Lawsuits followed, and federal judges were willing to grant injunctions on provisions deemed too restrictive and infringing on First Amendment rights. Only a portion of that original law is still enforceable today.
Many of the requirements in HR 4472 are nearly identical to the requirements struck down a year ago. I believe the Republican 'leadership' in Congress
knows that these requirements are unconstitutional, and are passing them anyway for two reasons: (1) it's an election year, and they need more red meat to throw to their base; (2) another round of litigation will be expensive for producers of adult entertainment, and while Congress can't make erotica go away, they can play games to eat up their profits.
I expect that the law in the form passed today will not stand, although some of its provisions may survive the legal process.
The
Free Speech Coalition, which Lex linked to in his original post, is an
outstanding champion in the ongoing battle for free online speech. Please consider sending a small contribution their way to help support their efforts.