Amazon.com may be planning to offer mobile phone service to its Prime subscribers. The Wall Street Journal reported Amazon has been in talks with wireless carriers about providing low-cost or free mobile service as a perk for its loyal customers.

This news sent shockwaves through the telecom industry. Shares of AT&T (T), Verizon (VZ) and T-Mobile (TMUS) all dropped by 4% or more in premarket trading on Friday.

I don’t know why this would scare investors in telecom companies. Amazon doesn’t have a cellular network. It doesn’t hold the rights to any cellular spectrum that I know of. In order to launch a cellular network they would have to lease network bandwidth from AT&T, Verizon, or T-Mobile. This would be a boon to these companies and good for investors. They could try a wi-fi network too but there is too much infrastructure to build to make that work. I don’t get it.