In this pandemic there are a lot of people who are speaking their mind without restraint. So, I was thinking about what phrase would describe that. I felt it had to do with like “open spout" or "faucet” but something of that ilk.
“There are those who are more measured and restrained, and then there are those _____ who only speak their mind.”
I believe the term conveys a negative connotation and is something in the neighborhood of an object that emits something, and is a popularly used idiom.