How Are Masks Harmful?

i was told that i was endangering people by letting them think that masks were o k, that they weren't harmful. And then i started this amazing amount of feet back that was mad at me from health professionals who are making claims that masks were harmful. So it was really startling. They were saying things like that wearing a mask would cause a full sense of security,. That people would become very reckless just because they were wearing a mask and do more dangerous things. Now, i may not be a verologist, but i am a sociologist, and full sense of security is something that's been researched a lot, and it sounds really clever. Like, maybe there's some weird trick