[biafra]

Do they block or throttle VPN traffic?

[ivarious]

Some ISPs throttle P2P/torrent. I don't know specifically about VPN.

[westbywest]

VPN tunnels that go over port 443 SSL are difficult to throttle w/o affecting other services. They'd have to throttle by destination address, which can be more complex when available VPN endpoints are geographically distributed.