I am careful but not MI5/CIA
-In HK safety not much of an issue but I NEVER
use my phone. Actually don't call for several reasons. Like the thrill of not knowing who is available. Making appointments means you really want to see so WG a bit too much IMHO.
Don't ever want a surprise call and carrying a punting phone has its own risks, like my memory (where'd I put that thing?)
-Other places safety is an issue. I agree, be aware of your surroundings, if you feel uneasy get out. Your gut feeling is probably right. Didn't follow that instinct once in Shanghai and paid the price.
[Golden role in Shanghai is never follow a toot you meet on the street.] Carry minamal cash and cards but I do have at least one ID.
You name? Who cares, they mostly can't remember yours among hundreds and I can't remember theirs. Although I keep a record of good sauna gals #'s, their sauna # not phone.