I just got my new laptop and began poking around in there clicking buttons to see what things were ... and yes, I too clicked the Air Drop button before I realized what gates I'd opened.
I agree with others, I am security conscious and just do not like the idea of having my computer's presence broadcast to everyone. And I really do not like that it's a default position and people like me, who is totally not a wizard, struggle with discovery. I don't quite understand why that is a good thing and why it is a default. It seems to me all of this should be something that one must work to turn ON as opposed to turn OFF.
At any rate, I too, shall await for the response on what to do now that I've clicked the button! laments ~Mac, why do you do such things to us non-wizards?~ Thank you for this forum and all the useful information you provide.