The proverbial phrase "separate the wheat from the chaff" may not be terribly meaningful to you — unless you happen to be a grain farmer. The chaff is the husk surrounding a seed, the part of the grain that is generally thrown away.
In cereal crops like rice, barley, oats, and wheat, the seed — the part of the plant that we eat — is surrounded by a husk. This waste material has been called chaff since the twelfth century at least, but the word has a long history as a metaphor meaning "objects and ideas of little or no value," as well. The Internet is full of misinformation as well as facts so you might have a hard time separating the wheat from the chaff. Their nasty comments are just a lot of chaff — don't even listen to them.