The rumble of discontent over new iPhone carrier Orange's rather limited "unlimited" data download restrictions rumbles on with news that data-rich applications such as Spotify and Facebook may be restricted.

Yesterday Orange was blasted by potential customers, including those posting comments on Macworld, for limiting its "unlimited" data to just 750MB.

Now it appears that Orange - unlike currently UK-exclusive Apple iPhone carrier O2 - will also effectively ban its iPhone customers from a host of internet services when it starts selling the iPhone from November 10.

Rory Cellan-Jones, the BBC's technology correspondent, was pointed to this clause in Orange's Terms and Conditions:

"Not to be used for other activities (eg using your handset as a modem, non-Orange internet based streaming services, voice or video over the internet, instant messaging, peer to peer file sharing, non-Orange internet based video). Should such use be detected notice may be given and Network protection controls applied to all services which Orange does not believe constitutes mobile browsing."

In his BBC blog today Cellan-Jones suggests that "it sounds as though services like Spotify, AudioBoo, Ustream and even Facebook messaging - increasingly popular with O2 iPhone customers - will be out of bounds for Orange users."

"If too many power users start streaming TV and playing online games on their phones, the Orange network may buckle under the strain - hence the need for a fair usage limit," explains the BBC man.

In contrast O2's fair usage terms state: "We reserve the right... to contact customers about their usage if we believe it adversely affects the service of our other customers, eg if a customer uses their SIM in another device for which it is not intended."

An Orange spokesman told Cellan-Jones yesterday that the cap would be "reviewed" to make sure that it was at the right level.

Cellan-Jones sees Orange as "caught between a rock and a hard place": "The problem for the operators is that users no longer see the iPhone and similar devices as phones but as small computers. And who wants to be told 25 days into each month that they must now stop playing around with their computer and just use it to make calls?

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