Iagree with PPs
- taking a picture of a car on the street: fine
- taking street dhots, or shots of public places generally, which coincidentally include people / children: fine
- Taking pictures in a way which inconveniences others, whether by blocking access, holding up lots of other people wanting to see / photograph the same thing / demanding people pose or get out of your shot : not OK
- focusing on or taking pictures of (identifiable) individuals without their consent: Not OK
I think taking pictures into someone's private property is a bit more tricky - in the orange tree example, for instance, I think taking shots showing the tree and the house/garden would be a bit intrusive. Taking a shot which showed ONLY an orange or two and some leaves would not strike me that way, although a the photographer I think the onus is on you to think about what it looks as though you're doing, as well as what you're actually doing.
With the dog example I think it's OK to take shots of the dogs, or a general landscape which includes the dogs, but I think taking a shot of the dogs and their owner puts it back in the category of shots of (identifiable) people - if you wouldn't take the picture if the person didn't have the dogs with them, it's not OK to take it when they do.
(edited due to premature posting)