transit across the ixs

you might be amused to write a bit of code to see if your ix peers are giving you next-hops of other provider(s). it is clear that a number of providers are selling transit across the ixs. not at all cool. we can't decide whether to force next hop on their routes, or keep watching and de-peer them if they do not cease and desist. what do others do in this circumstance? randy