I suspected the thread would make a fuss, everyone is so into meaningless virtue signaling these days. So, sure - feel free to post about how high and mighty you are and would never trample on others wishes. We (anonymous folks) really look up to you. Feel better?
1. It's legal nearly everywhere (as far as I know to take photos in public spaces - on the street etc). With the exception in some countries of public buildings (airports, govt architecture) and in other countries some religious spaces. Er.. and of course I guess nude beaches

I'm not talking about North Korea here.
2. Rocks were thrown not just because I had my camera - but because I was white, there were four of us and we all got rocks thrown at us - the crowd quickly intervened and stopped the teenagers and apologized (but suggested we leave). I was just saying - how much worse would it be if I were photographing. I sincerely doubt the camels would have minded too much - and it was a public market that many others have photographed in the past - it's just that sometimes sh*t happens.
Other places, as soon as you whip out your camera on the street some goof will run up to you and demand money, this isn't a person that cares about his picture taken, this is someone that does this day in/out to try to get money from tourists. Even had this happen in Jamaica - but mostly in Africa. It can get ugly (largely a strategy to cow you into giving money).
3. If you carry a large DSL you run the risk of being seen as a reporter / journalist. This can bring requests to see journalistic permits etc etc - or worse. Essentially it's often best to keep a low profile.
If there were a way to snap a few pictures while walking down the street of old buildings, or street life etc without having to whip out my camera or even iPhone it would only be a cool tool to have.
Yeah, I'm a novice tourist who has only been to Paris and London.. lol - er.. and 104 countries and counting - how about you (the one that are virtue signaling)?
Anyway - I found a camera that might work - it's a button cam with reasonable resolution. I'll give it a try and see how it goes.
Thanks for those that gave 'real' advice - yes, sitting down in a place and letting people get used to you always helps. Have done this often. But sometimes - like in the middle of an african money market - no matter how long you sit in the street you're not going to look very normal.
A photographic guide can also be incredibly cool - they know all the good places and times of days / light. However, you'll be hard pressed to find some in many parts of rural Africa.. Not to mention budget.