Well we have "a lot" of prickly pear cactus at Timucua Forest - it spreads from being cut / mowed any small piece can sprout roots and grow. The current plan is to dig up lots of them in our walkways and camping areas but this is a real project. Prickly pear is not just a nuisance it is very eatable (you have to get past the spines) How to Cut and Prepare
There also seem to be health benefits see this WebMD article on Prickly Pear -- "Prickly pear cactus is used for type 2 diabetes, high cholesterol, obesity, alcohol hangover, colitis, diarrhea, and benign prostatic hypertrophy (BPH). It is also used to fight viral infections."