Re: Who needs a law?
Under Senator Wyden's proposal, they could do every one of the things you mention to whatever extent they may do at present. As for courts granting immunity to those cooperating with warrantless wiretaps, I think we have known about that for something over half a decade, and got Section 215 as a patch for it. Senator Wyden's proposed act also maintains, explicitly, the existing CALEA requirement for telephone system backdoors.
There is some reason to doubt that we need a law to forbid the government from doing something no law permits it to do, and also to suspect that those sponsoring such legislation are engaged primarily in grandstanding for their own benefit, after the manner of most politicians.
Biting the hand that feeds IT
