I think in light of the Snowden revelations, everyone in the U.S. would be right to be suspicious of such an offering. Except of course those that have nothing to hide. Of course, if you're not using the nation's free wifi, then you're clearly up to no good and deserve a warrant for suspicious behaviour ;)
At this point, everyone's threat model should include a well funded government. Of course, like everything else, you have to weigh convenience against the cost of security. At some point you have to throw your hands up in the air and say "whatever!" if they want to find something against me, they will surely find it. I think it was Cardinal Richeleu who was supposed to have said "Find me 6 lines by the most honest man and I will find in them something to have him hanged." [I paraphrase]
The point is that moving away from free government provided WIFI does nothing to prevent the US government from getting anything they want, and it is dangerous and irresponsible to suggest otherwise. We know this because the US doesn't have government provided WIFI and they have an estimated 3 to 12 exabytes of planned storage at the Utah Data Center. (Where 5 exabytes would be "all the words ever spoken by humans").