I was watching a pair of local swans with their babies. A woman came along with her children and told them out loud to keep away from the swans as they were dangerous that I was being stupid for standing where I was (a few feet from one of the adults and further from the cygnets). I asked her not to call me stupid and she retorted that the swans were dangerous. I pointed out that I knew what I was doing and didn't appreciate being called stupid and she walked off in a huff without an apology.
I have a lot of experience of being around swans in general and this pair in particular. If I get closer than the adult birds would like they will warn me by hissing (which they were not doing). They are powerful but will only attack as a last resort and I was keeping a close eye on them and ready to brace myself.
Whilst this woman wouldn't have known that I was well accustomed to the birds she I don't think she had any business to make a judgement about a total stranger without knowing the facts.