First, it won't form a monopoly. There will be 2 other major carriers besides AT&T. Second, yes, anybody can argue against the merger, but all it does is put off the inevitable. Hell, I bet in a ways AT&T might even hope it gets blocked. Then, they could just buy the spectrum at firesale prices. But, either way, just the announcement of the merger sealed T-Mobile's fate. At least with the merger, the employees have a chance at a job. If DT piece-meals out the assets, then nobody at T-Mobile will have a job, and there will still just be 3 major carriers.