Maybe we should just stop protecting the stupid. The fact that the cows were protecting their calves is only natural. I tell everyone that even though I don't buy into it the evolutionists believe the stupid shall perish. This was just evolution taking its course according to them.
In much of Europe, a concept called "everyman's right" gives walkers/ramblers/hikers/meanderers etc the right to walk through the countryside. You are not supposed to approach animals or buildings, pick stuff or litter (etc), or (I think) camp.
When we hiked in Ireland, there were little turnstiles into the fields, or steps over the fences. The farmers would wave to you from off in the distance. Once we saw a big rock at the farm perimeter, spray-painted "Beware of bull in field."
This isn't going to stop anything. People know that bison are miserable creatures, yet every year I read an article where some moron got themselves skewered b/c they wanted a video. People are stupid, you can't protect them from themselves. Unfortunately, the dumb ones seem to breed way more than the intelligent ones and they usually do it before they're removed from the gene pool.