An anonymous user proposed an edit to an answer. I doubt the information in the edit, but I can't say for sure that it is wrong. It states that 1) the relaxing agent in pizza yeast is called "L-cysteine", 2) using yeast with L-cysteine leads to bad-tasting crust, and 3) the author doesn't use it because "it is synthesized from human hair and duck feathers and imported from China".
The last statement makes me doubt the credibility of the author - first, I don't think any foodgrade chemical is synthesized from human hair, even if it is technically possible. Second, it smacks of panic-mongering (what is wrong to eat something derived from duck feathers?). And the reduced credibility makes me doubt the other two statements.
If this had been a stand-alone answer, I would have left a comment asking for sources for these rather strange claims, and maybe downvoted because of the confrontational phrasing. If I had knowledge on the subject matter, I would have improved the edit before accepting it. But as it is, I can only imagine accepting or rejecting it. Accepting would result in potentially wrong and badly worded information appearing as a part of the original author's answer. Rejecting results in the loss of potentially true and helpful information on the topic. Also, making this information part of somebody else's answer forces the community to judge (up- and downvote) all as a unit, instead of giving it a way to up- or downvote the new information only.
What is the correct way to resolve this situation? Rejecting the edit and posting it as a new answer, adding the disclaimer that it was originally written by somebody else? It is especially unpleasant that it was an anonymous edit, so I can't attribute it to its author. Or maybe leaving it there in the hope that a mod will have the time to research the subject enough to find out the truth content of the edit and preserve the true parts? I don't think we have active 10k users who are not moderators.