Eight leading American technology firms have called on the United States President and Congress – and their counterparts around the world — to rein in government surveillance.

Microsoft(s msft), Google(s goog), LinkedIn(s lnkd), Apple(s aapl), AOL(s aol), Yahoo(s yhoo), Facebook(s fb) and Twitter(s twtr) said in an open letter on Sunday that they were all encrypting their systems and “pushing back on government requests” for customer data “to ensure that they are legal and reasonable in scope.” However, the firms said, they need President Obama and Congress to “take the lead on reform.”

Specifically, the companies said that:

• Governments should avoid bulk data collection of internet communications, instead limiting surveillance to targeted situations.
• There should be a clear legal framework for surveillance by intelligence agencies, with independent oversight courts that allow an “adversarial process” – i.e. there’s someone around to raise the arguments against surveillance in any given case.