Bill, it's not about protecting themselves but (usually) the rights of programme makers, performers etc. The BBC web presence is certainly the biggest in Europe and probably in the world (which raises some questions in the UK about its remit), but so far the Beeb has baulked at paying out for worldwide on-demand rights. There would also be additional bandwith costs etc.

Good one, Tom! I've just got back from watching gypsy trumpet bands in Bosnia in time for Warwick, so see you there.....