Chameleons are a non-native species in Florida. They've gotten a foothold through illegal "chameleon ranching" by breeders. Enter reptile enthusiasts who call themselves herpers and who go out at night to catch these free-range invaders for fun and profit.
Via National Geographic:
Herpers are a small but dedicated community who share herping tips and favorite chameleon hiding spots on private online forums. Even more underground—and sometimes controversial—are chameleon "ranchers," who breed and raise the reptiles with the intention of selling them off.
Most of these ranching activities go unnoticed, since it's hard to prove whether a chameleon rancher deliberately—and illegally—introduced the initial chameleons, or just happened to already have them on his or her property.
Ranching can be lucrative; a panther chameleon, one of the Florida non-natives, can sell for up to $1,000.
And it's not hard to wrangle the small reptiles. They're predictable homebodies—generally settling in one spot—as well as fecund: A chameleon pair in one small area can yield an entire micro-colony in just a few generations. Why import chameleons from a distant country like Yemen when you have an unlimited, free supply in your backyard?