Assuming for the moment that the allegations are true, AT&T would not go along with blatant violation of telecommunications laws out of the goodness of their hearts, out of a sense of patriotic duty, or for a mere promise of legal indemnity. They got something. Or were promised something.
What was their quid for the government's quo?
Smooth sailing for the SBC merger? (Like it wasn't going to happen otherwise?) Cash up front? A promise not to be punished for not cooperating? (The Bush administration saves its sticks for non-corporate players.)
Here's another possibility:
"Congress is going to hand the operation of the Internet over to AT&T, Verizon and Comcast." [more]
Matt Stoller at MyDD quotes this interview with Edward Whitacre, the CEO of SBC Communications (now AT&T):
How concerned are you about Internet upstarts like Google (GOOG), MSN, Vonage, and others?Follow the money.
How do you think they're going to get to customers? Through a broadband pipe. Cable companies have them. We have them. Now what they would like to do is use my pipes free, but I ain't going to let them do that because we have spent this capital and we have to have a return on it. So there's going to have to be some mechanism for these people who use these pipes to pay for the portion they're using. Why should they be allowed to use my pipes?
The Internet can't be free in that sense, because we and the cable companies have made an investment and for a Google or Yahoo! (YHOO) or Vonage or anybody to expect to use these pipes [for] free is nuts!