And mustangs should run wild and free!
Why? Like artgecko said, they're not "wild" horses. They're feral. The last
real wild horse I know of is the Przewalski's horse, which are endangered.
Wikipedia says: Most "wild" horses today, such as the American
Mustang or the Australian
Brumby, are actually
feral horses descended from
domesticated animals that escaped and adapted to life in the wild. In contrast, Przewalski's horse has never been domesticated and remains the only truly wild horse in the world today."
Source:
http://en.wikipedia.org/wiki/Przewalski's_horse
Mustangs were never meant to run wild, but regardless of that, they have no more right to that land than deer and other native wildlife. Less of a right, even, since they are not native. Ranchers have a right to fence land owned by them. If they're fencing land that isn't theirs, that's a whole 'nother problem unrelated to Mustangs.
While I don't agree with some of the methods used to control Mustangs and I do think horses running free is one of the most beautiful things in the world, I think Mustangs would be better off if all of them were rounded up and given to good owners. They were never meant to fight for survival. They're domestic animals and it is almost cruel to force them to continue to live off land that can barely support them and fight predators, unprotected by the humans that created them. They are also taking resources from native wildlife.
I will add, though, I hate humans encroaching on land that SHOULD belong to animals and destroying it, but it is a fact of life now. All we can do is try to do right by the animals' whose lives are ruined by human interference.