Spot of thrush

A pair of Song Thrushes have clearly got a nest near our garden and are spending a lot of time gobbling worms from my lawn. I expect the vast amount of snails, grown fat on my bedding plants, attracted them in.

My blip yesterday elicited a lot of (offline) discussion. Is it ethically ok to take candid photos of strangers without their permission? I must say that before I was challenged on it I assumed - through years of seeing street photography in newspapers - that it was fine; now I'm not so sure.

Be interested in hearing the opinions of any other blippers....