Verizon Wireless, Comcast, Time Warner. and Brightline Cable have come together over a deal to alter how people use TV, cellphones, and the Internet. Verizon Wireless has agreed to pay the three cable companies $3.6 billion for cellphone airwaves that they own but are unused. Not only would this deal make Verizon’s service the most dominant, it would allow Verizon to sell the cable companies’ products and vice versa. Regulators immediately signaled concerns about the antitrust implications of the deal.