You cannot as easily be held hostage. I have consulted for a few ISPs and have my share of war stories.

Here's a (true!) example. One day, a certain head of a fairly large ISP decided that he wouldn't route traffic to or from IPs he had assigned that didn't reverse resolve because he felt it was imperative that people be able to find network contacts in this way (I think he got sick of being the one to get the abuse emails). He told my client three days before implementing a sweep and filter. He had the equivalent of about 38 /24s from this ISP distributed over about 180 customers, they were his sole uplink.

[SNIP] Often overlooked is the redundancy in business processes. We tend to view events with an external-forces engineering perspective while frequently the culprits are uninformed decisions, knee-jerk reactions and opportunism by humans at our vendors. (Not to downplay other risks.) -John -- John Ferriby - PGP Key: www.ferriby.com/pgpkey