Although I can well believe the Beeb blocking stuff, but why ITV?
Because, just like the BBC and any other TV channel in the entire world, their transmitted content is either in part or in whole comprised of content owned by other rights-holders with whom they have reached a commercial agreement.
This can be anything from the entire TV programme being produced by an independent production house, through to the soundtrack. Whatever it is, a large part of the commercial agreement reached between the broadcaster and content provider will be a restriction on geographic transmission. This is both beneficial to the broadcaster (as the smaller the geography, the smaller the licensing fee), as well as to the content provider (being able to keep prices competitive by allowing them to sell the same content in multiple geographies at the same time).
Therefore, please respect copyright and don't attempt to bypass it. It is illegal.
Please also note the Computers & Internet forum guidelines which state
This forum is NOT a place to enquire about circumvention of copyright (even MS products) - any such posts will rapidly be deleted and the culprits hung, drawn and quartered.
If you wish to discuss copyright circumvention, Mr Google will no doubt promptly guide you to the darker parts of the internet....