I could get behind something like that, though I do wonder how big a difference that would really necessarily make. Cell phone network providers have to lease spectrum ranges from the government, but it's not as if that market is actually robust. Beyond that, Congress is perfectly able to pass regulation on ISPs, but doesn't for a variety of stupid political reasons. I'm not sure how those couldn't equally apply to USPS oversight (perhaps even more cheaply, since you'd have fewer people to bribe I mean, lobby).

I don't really have an issue with in in principle, but I'm not convinced it would inherently make things much better either.