The government can be sued for warrantless wiretapping. The telecom companies can't.

LA Times:

Residential telephone customers can sue the government for allegedly eavesdropping on their private communications in a warrantless "dragnet of ordinary Americans," a federal appeals court ruled Thursday.

The three-judge panel of the U.S. 9th Circuit Court of Appeals, however, upheld dismissal of other cases that sought to hold the telecommunications companies liable, citing Congress' decision to grant them retroactive immunity.

I'm kinda-sorta OK with this outcome. The telecom companies facilitated the eavesdropping at the government's behest; targeting the companies for their participation was always a way of trying to hold somebody accountable for the government's illegal actions. I'm no fan of big corporations, but if the government that has regulatory power over you prompts you to do something illegal in the name of preventing terrorist attacks—well, I imagine that prompt would be pretty difficult to ignore. The government's responsible here; let's hold the government accountable.

That said, remember: Then-Senator Obama voted to give the telecoms immunity. It was an early indication that maybe he wasn't quite as committed to the civil liberties cause as we hoped.