I don't care whether Americans make money suing telecoms. I think this is in the competence of a court to judge, but don't think it's terribly important. The telecoms were not the instigators of what happened (see Kevin Drum writes about why he symapthizes with the telecoms).
What is important is the administration got its way, preventing the disclosures these cases would bring. That is unfortunate. Telecoms are merely scapegoats, the people responsible for what happened have already been let completely off the hook. Josh Patashnik, like Kevin Drum, sympathizes with the telecoms.
It's worth emphasizing, though, that there was an ideal solution to this problem: the Specter–Whitehouse substitution amendment, which would have allowed lawsuits to go forward but would have substituted the United States as a defendant, letting the telecoms off the hook. But the administration, Senate Republicans, and a handful of Democrats conspired to kill this amendment. The primary reason the Bush administration wants immunity isn't to help out its telecom friends, but to prevent the details of the wiretapping program from being scrutinized--even confidentally--in a lawsuit, regardless of who the defendant is.
I don't really sympathize with the telecoms, but obviously they're not the really wrong-doers. The government giving them immunity was bad, but the real scandal is the government giving itself immunity.
You may recall Republican complaining the telecoms were ungrateful, in that they didn't give the Republicans enough contributions to compensate for what Republicans were doing on their behalf.It makes sense to me. Big businesses hedge their bets, and the telecoms were probably in no mood to be grateful, having been put in this uncomfortable position by the administration in the first place.
They knew the Republican would vote for immunity, simply to cover for the administration. If I were running one of those companies, I'd concentrate on the Democrats too.