What is the origin of the idiom "for what it is worth" and when to use it?

The idiom "for what it is worth" is often used to preface an opinion or statement, expressing the speaker's sense of humility or uncertainty about the value of their input. Its origins can be traced back to the 1966 song "For What It's Worth (Stop, Hey What's That Sound)" by Buffalo Springfield, which captured the social and political turmoil of the era. The phrase has since become a common idiom, used in various contexts to convey tentativeness or a lack of absolute confidence in one's words.