YourMobileGuru
Formerly VZWRocks
Where would they go? AT&T no longer offers unlimited data and throttles unlimited data after 2GB anyhow. Sprint doesn't have 4G LTE very many places and neither does T-Mobile.
A lot of them go to TMobile or Sprint who advertize unlimited data but of course the performance just isn't there.
Oh and Straight Talk, but now they are starting to throttle more aggressively as well, so we will see how long that lasts.