I've been doing my browsing through a VPN hosted on Amazon.
(Due to increased governmental and recording industry snooping, I'm working on alternatives to traceable IP addresses. I'm not actually doing anything "bad" myself).
Stack Overflow is blocked and says "only API requests are accepted from this address". Is there a good reason for this? Especially as I'm using a static (elastic) IP which is tied to my user - it's not like an open proxy.