I respectfully disagree with "hiding" trails. I'd be all for it if it worked.
In the opinion of my local club presidents, it accomplishes nothing.
What's required is enforcement, which for some reason, the government will not provide, or allow the clubs to have any enforcement tools.
Every trail I drive by in my area that isn't through a corn field is a mucky rutted mess. Boulders and barriers are winched away.
I'd like to see the stats of actual arrests and convictions for trespassing.