Men are absolutely a potential danger to a woman. Not all of them, or even most of them, but women should behave as though any strange guy, whether you are walking down a lonely dark street or on a blind internet date, are a danger. I can't vouch for any man I don't know personally, but I know from experience that a lot of guys are assholes, and I know from reading the news that there are many more male criminals than women. Women cannot go out clubbing and expect that every guy with nice teeth who can afford to buy them a Grey Goose Cosmo is good guy.

Don't trust any man until you have met other people who know them. Dudes, the same with the ladies.