NSA's PRISM system is quite the beast indeed, but now it is being revealed that the US security agency have been intercepting SSL traffic too - which is meant to be a secure link - after all, it stands for secure sockets layer.
Obviously not, as the US security agency have been using their PRISM system to gather and store huge quantities (see: all) of SSL encrypted data for later cryptanalysis. Netcraft also reports that this huge volume of data is logged so that if an SSL private key later becomes available, they can be decrypted.
There are 'legal' methods of getting these private keys: a court order, social engineering, an attack against the website, or through cryptanalysis. But, it's the NSA - do you really expect them to use legal means to break your encrypted data that they weren't meant to take in the first place? Yeah, I thought so.