Apparently people are still missing the point. On a shared media
exchange, there is nothing to preclude another entity from pointing
default to you even if they are *not* peering with you [a.k.a. bit-dumping].
Sure there is. Write a perl script to monitor such things. It takes about
30 minutes - plus another 30 minutes if you want to spiff it up and document
it. This assumes you've used a perl-expect type thing before.