Rebtel, a Luxembourg and Sweden-based start-up that provides cheap international mobile calls, has been blocked in Germany by operator O2. \nRebtel has found a way to take expensive international calls out of the hands of the mobile operators and make them cheaper by using the Internet. The Word Wide Web functions as a rerouting system that connects local calls around the globe. Users receive an alternative number that\u2019s connected to the number they want to call. There go the operator\u2019s margins.\nHere\u2019s Rebtel\u2019s side of the story, as expressed on their blog:\nThe reason why O2 wants to stop Rebtel is pretty obvious. They have very high margins on their international calling and want to stop any threats to that. Their actions violate not only the crystal clear EU-regulations but are also a breach of your contract with O2(!). \nThe mobile technology company has now started a so-called \u201crace\u201d with O2. Like a true reb(t)el would, they\u2019ve just launched another series of numbers. Which, of course, O2 will block as soon as possible. Although Rebtel\u2019s fighting spirit is admirable and charming, the service does become unreliable for O2 users. We\u2019ll keep you posted on how the race develops.