Telling people not to do something is a sure fire way to get them to do it. Human curiosity is strong.
How exactly does that make it OK to be disrespectful of other people's property and privacy?
For instance, in (some parts of?) the UK there's the Right to Roam, I believe, which grants the public limited rights to pass through certain private property (such as an open field). Obviously this doesn't extend to harming anything. The point is, passing through someone's private property without causing any damage or inconveniencing them is not automatically considered unethical.
If it’s not someone’s home, and you are not engaged in nefarious activity, you will not be shot for trespassing. You will be told to leave.