I confess I’m too shy to stop and ask to take a picture. There are those who say the spontaneous moment is lost as soon as someone poses. I’m shy. So just point and shoot. Remember, shutter 1/100. Wide angle setting and the autofocus will save you, mostly. You end up with lots of duds. And then there are interesting keepers. Here and there you take a little time to compose. Not much time, remember, I’m shy and I don’t want a confrontation. Interestingly I stand out as a foreigner. And I am ignored. I walk invisibly and observe a foreign culture and am largely ignored. Nighttime is when the market is hopping. Smartphones are pretty much everywhere.
Wallet? I think that my wallets are all from street vendors – under $10 – my price.
As to legality, you are legally an unwilling target whenever you are in public. However, you do not want to be confrontational. The caveat, don’t be noticed, and don’t invite controversy.