-Points to the first reply to this thread- That much regarding reporting those who "rape" other users. Reporting that behavior should always be something to keep in mind, and not something to tolerate.
But, as for the cows themselves, I've definitely seen these floofballs running around, and as I believe I might've seen the first few users who started this frenzied moo-fest. In fact, when it first started happening, I observed them numbering almost 10-15 in Bonfire, and to be honest the names they had for them (Stew, Beef, Veal, Cheese, Milk, etc.) were really pretty funny.
And ever since, they've been a thing.
While I don't think the cow fad is going to last all that long, I do find their sense of humor amusing, so long as they stay within game rules.