"It depends on what ISP you're talking about but not all ISPs [currently] log network address assignment," said Bankston. "For example, T-Mobile does not log IP address assignments through its mobile devices [and] based on testimony in an earlier data retention hearing there's at least one major cable internet provider that does not log IP address assignments."
There's also a question of how long the ISPs track data.
"It may be that companies log these assignments for a short period of time but not for the full year that the bill would require," he added. "But if you're asking what exactly are the practices of all the major ISPs, I think that at this point it is an unanswered question and one that's worth getting answered, particularly to the extent that it might mitigate a need for such legislation."
From here, the bill is headed to the floor of the House of Representatives.
What are its chances for staying alive once Congress gets to it after dealing with the testy debt ceiling debate?
"Some key Republicans opposed the bill and some key Democrats supported it so this is one of those bills that tends to come up late in a session because it's controversial. I think that its prospects will be determined in part by whether Tea Party Republicans see it as a power grab by the government," Nojeim said.