>Isn't trespassing, regardless of what you do once you are on private property without permission, already illegal?

In most states you have to follow pretty strict rules around how and what you post in regards to no trespassing signs - and a failure to properly post is an automatic granting of rights to the property. Furthermore they'd likely have trouble actually following the letter of the law given the amount of "unknown" people that need to go in and out of the farm on a daily basis for deliveries/etc.

In other words - if you've got 30 truck drivers a day coming and going, and you haven't given each and every one explicit permission to enter your "private property", you likely have no grounds to sue the person you didn't want there. There is no concept of assumed rights that I can find in Montana law.

http://codes.findlaw.com/mt/title-45-crimes/mt-code-ann-sect...

well, a violation of a minor law as a necessary step to stop bigger and much severe crime ... Or imagine somebody is having what looks like a heart attack and is falling onto a somebody's lawn, ie. private property, from the sidewalk - stepping onto the lawn to help would technically be the crime of trespassing, wouldn't it?

Actually, there are protections built into the our system of justice for incidental violations of the law like this where there was no criminal intent. Killing someone with your car is a potential violation of a whole host of serious statutes - potentially all the way up to first degree murder. But if it is determined to be an accident and there aren't other factors (intoxication, extreme negligence, etc.)...you cannot be prosecuted for that.

Some of them trespass, yes, but most of the filming is done from the outside using a powerful zoom lens, or from a drone, or more commonly, by an employee with access to the property.

Right, but what I was referring to was this:

The Utah Legislature approved a bill in 2012 that made it a class B misdemeanor to trespass on private livestock or poultry operations and record sound or images without the owner's permission.

So this particular law seems like a solution without a problem, given that trespassing for any reason is already illegal.

In the statute, actually they specifically list reasons that make your presence a trespass.

https://le.utah.gov/xcode/Title76/Chapter6/76-6-S206.html?v=...

Entering property for just any reason doesn't count as trespass... you need to have some sort of malicious intent, and stay despite being reasonably warned (including by signs or a fence) that your presence is not welcome.

If i understand correctly it's not that it wasn't illegal before, rather it wasn't a class B misdemeanor. I'm not a lawyer though.

It is already illegal, but now you can be charged with more offenses than before. Also, the penalty may possibly be higher than for trespassing (didn't check if it's true).

It seems to be a common thing in the US. In similar way, IIRC some states have laws which make it a separate crime to use a firearm to murder someone or federal telecommunication law apparently penalizes using telco networks for obscenity and harassment which is something Title II Net Neutrality opponents like to complain about.

Many undercover films are made by people who have the landowners permission to be on the property.

And isn't trespass a civil law thing, rather than a criminal law thing? So this law created a criminal component that could be charged.

Trespassing is a criminal offense in the same vein as breaking and entering.