That would be relevant if the state governments were banning display of these videos. But free speech rights have never encompassed regulation of what you can do on private property without the consent of the property owner. It's not any more unconstitutional (note, as usual, the disclaimer that just because its constitutional doesn't mean its a good idea) to make a law that bans video taping on private farms than it is to make a law that bans me video taping your wife in the shower in your house.