Section 702 of the Foreign Intelligence and Surveillance Act (FISA)
Under Section 702 of FISA, federal investigators do not need a warrant to tap the phone calls, texts, and emails of foreigners outside of the country. But a loophole also lets them access messages that Americans exchange with targets abroad.
Unfortunately our legal system doesn't require the review of every law for it's constitutionality before it gets passed. To fight the issue on constitution grounds someone would need to sue the government for violating their rights this way.
As I understand it, there's really two loopholes. One is that they can scoop communications in either direction from the particular communication in question, so could be American to American or foreign to foreign. The other loophe is all of this is put into a database that other agencies can access without a warrant, meaning your domestic communications are freely available.
They're covering their eyes but peeking between their fingers.
Snowden says all this has never lead to them preventing and stop a terrorist attack. Wonder if that's still true. If so, why tf would they renew this program?