Really? Users shouldn't be afraid of the consequences of something they believe to be benign? I didn't send Starbucks patrons home weeping to cry themselves to sleep. I fully concealed my identity in the same way an actual attacker would.
You are not a hero. You have not done anybody a favor. You did this for the same perennial excuse of "spreading awareness" trotted out by any number of noxious social irritants and did so not by the means most efficient or effective, but the means readily available and most likely to satisfy your urge to feel superior to your fellow man.
You may actually care about the problem and take it seriously in other circumstances, but that is not reflected here. There is no security problem for which "exploit the problem to harass strangers in coffee shops" is the solution.
You should probably replace "harass" with "inform" in your comment. It would be more accurate, and less emotive.
Suppose you leave it be for the day. You've got more important things to do than blindly react to mysterious messages, haven't you? So day slips into night and before long it's morning again. You find another note:"Really wasn't kidding about the bars thing. I won't send another message after this -- it's up to you to take your security seriously." Same as before, nothing obviously missing, all windows and doors closed and locked. You have no idea who this is or why they are doing this. You have no idea if you can trust them.
How do you react?
That sounds exactly like a distinction to me. A fireman would break into a house to save a child. A burglar would break into a house to steal valuables. One intends harm, the other doesn't.
> did so not by the means most efficient or effective, but the means readily available and most likely to satisfy your urge to feel superior to your fellow man.
There's no such thing as true altruism. Why he did it isn't relevant. People feel good about doing good deeds. Sure, they say "I want to help people," but they really mean something more along the lines of "I want to feel good about myself."
Further, why would it be necessary for him to choose the most effective or efficient means? He owes these people nothing.
> There is no security problem for which "exploit the problem to harass strangers in coffee shops" is the solution.
Maybe not the best or even a good solution, but it's certainly still one. ;)
...but then...
Why he did it isn't relevant.
I am at least as uncertain as to what your position is as you are. Also...
He owes these people nothing.
Nothing, of course, except the common courtesy of not violating their privacy. Yes, even in New York.