I think you better learn if you did not know before. Government could alway listen to your conversations if it wanted, legally, with a warrant.
But with FISA, which President Bush signed (Foreign Intelligence Surveillance Act) Amendments Act of 2008 into law, it does not need warrants. John Edwards of VoIP News has done a better job of describing the procedures that the government may use for the surveillance and collection of "foreign intelligence information" between "foreign powers" and "agents of foreign powers." Read and educate yourself.