You'll have to scroll down past a few very interesting pages to get to the VPN cracking stuff, but the NSA can pretty much compromise whatever VPN they want to:
http://www.spiegel.de/international/germany/inside-the-nsa-s-war-on-internet-security-a-1010361.html
One of those interesting bits is what it takes to actually give the NSA a real problem:
"Things become 'catastrophic' for the NSA at level five - when, for example, a subject uses a combination of Tor, another anonymization service, the instant messaging system CSpace and a system for Internet telephony (voice over IP) called ZRTP. This type of combination results in a 'near-total loss/lack of insight to target communications, presence,' the NSA document states."
http://www.spiegel.de/international/germany/inside-the-nsa-s-war-on-internet-security-a-1010361.html
One of those interesting bits is what it takes to actually give the NSA a real problem:
"Things become 'catastrophic' for the NSA at level five - when, for example, a subject uses a combination of Tor, another anonymization service, the instant messaging system CSpace and a system for Internet telephony (voice over IP) called ZRTP. This type of combination results in a 'near-total loss/lack of insight to target communications, presence,' the NSA document states."