DEC's PAIX agreement specifies "...and provider agrees not to point default at any other PAIX member" or some such. This means stealing unitransit in Palo Alto is a terminable offense. Other interconnects ought to do the same. I note this because CIX member at PAIX asked to have port filtering installed on their GIGAswitch port just because they were afraid of people pointing default at them. That meant that some other CIX members who were using the CIX router as a sort of poor man's route server had to set up direct peering. Probably direct peering is better for network stability in any case (recalling the MAE-W route server failure last year that took a week to fix) but the fact of the worry bothered me. There is no cause for such worry. Nobody is going to point default at you by accident; if they did it, they did it on purpose, and they don't belong at the exchange point at all.