Equally if you can't control them. Mrs Wisdom is scared of dogs after one bit her and had to be put down, so having three black labs hurtle up to her growling at each other was not a good experience!
Owner of them couldn't understand why I shouted very loudly at both dogs and her; 'they don't bite'. Well, you might know that, I might guess that (but wasn't so sure as they approached at speed!) but Mrs Wisdom certainly didn't know that!
To be clear, don't mind dogs off leads if they obey orders(!) There's a very chilled little terrier we meet quite often on walks that comes and has a sniff, then trots back off to its owner on a quiet call. But get them to that stage before you let them off leads around other people!