Based on my personal observations here in Southwest Florida and what studies I've seen, I have to agree with game warden Fitzpatrick from fossil_digger's post. The wild hogs I frequently observe have to constantly be foraging for food to survive at all, with the largest I've seen being about 5 feet in length and maybe 250 to 300 pounds. In fact, most of my sightings are only possible because they're so busy eating that they don't notice me sneaking up on 'em. In order to get much larger than that someone would have to be feeding them a very rich diet making them not so wild after all.