If you are going to go urban exploring, always get permission from the property owner or their legal representative before exploring.
Something I routinely see on Facebook and other social media sites (I include Quora as its users are probably as bad if not worse than Facebook users). I saw somebody called a buzzkill because they advised against giving people advice on how to sneak past security guards to go urban exploring.
For starters, be it a military base (abandoned or in use), an old missile silo sold to an individual, or private property owned by individuals or a company, it’s generally private property and the legal and financial costs to trespassing vary based on state and local laws. Plus, many of the sites aren’t kept up so you risk getting injured or dying and if you were unwise enough not to let somebody know where you were going and when you would be back, what could have been a minor injury could lead to death. This doesn’t include those areas patrolled by security guards who may or may not be armed. Some security guards are professional enough they won’t shoot you on sight, but a jumpy guard no matter how experienced could accidentally shoot you. It also doesn’t include if you get into a fight with the guard and the guard gets injured or killed. That’s also not counting those who are sometimes engaged in illegal activities at these sites.
I watched enough YouTube videos of people doing urban exploring who got injured that it’s only a matter of time before somebody winds up dead if it hasn’t already happened.
Another problem involves liability if you give advice or encourage illegal activity. You could potentially be held liable as an accessory – before, during, or after the fact. Again state and local law will probably determine if you can be held liable and what the criminal, civil, financial, etc. liabilities you may face. Not exactly the same thing, but there was a recent swatting incident in Wichita, Kansas where somebody encouraged the swatting and an innocent person was killed by the police. There are at least two people awaiting trial in this case.
Worth noting the above applies to encouraging any kind of illegal activity on Facebook, Twitter, or other social media and isn’t only limited to urban exploring related activities.
Standard legal disclosure: this is not intended as, nor should it be construed as, legal advice. Always consult an attorney familiar with the type of law you want advice about.