Someone correct me if I'm wrong, but if most of your communication is over GMail/Google talk/Skype/Facetime/etc, there isn't a way the feds could wiretap that without the cooperation of Google/Microsoft/Apple, and AFAIK, they will require a warrant.
1) You do not need cooperation of those services if you sit on the network in between the end-user and the service. We know that the NSA does.
2) Securing cooperation does not require a warrant. Information can be requested by the FBI using a National Security Letter, without a warrant, simultaneously collecting information while gagging the service provider from informing the customer their information was collected.
http://en.wikipedia.org/wiki/National_security_letter
3) Any person's communications can be wiretapped by court order from the FISA court, separate from our normal court system. The FISA court judges see only evidence from the Department of Justice, and no information about their hearings is ever released or even recorded. Between 1979 and 2009, the FISA court has only declined to issue a court order for surveillance 11 times out of thousands.
http://en.wikipedia.org/wiki/Foreign_Intelligence_Surveillan...
2) Wikipedia says that "from 2003 to 2006 the bureau issued 192,499 national security letter requests". That's a long shot from the mass surveillance affecting "millions of Americans" (from this article), or the NSA having "a dossier on every citizen" (recently here, as well).
3) Good point.
http://www.wired.com/threatlevel/2012/05/google-nsa-secrecy-...