backbone transparent proxy / connection hijacking

Yeah, it tells you when to change vendors.

Yeah, to Digex, if you're an end user who doesn't want
to try to share your ISP's bottlenecks with hordes of
"mice" traffic in the form of short HTML transactions
which react so badly to congestion en masse that other
flows likely never reach equilibrium.

In short, if you want to run a VPN and have a decent
degree of performance, look to an ISP who either _really_
does no overbooking (rather than just says so) or
who overbooks but who uses this kind of mandatory caching
scheme and RED in combination.