There were some news reports on CCTV (that is, China Central Television, not closed-circuit TV), and an associated article published on the Internet Journal of Toxicology (supposed to be reputable). The Chinese government have also performed some crackdowns and introduced explicit banning of human hair. Of course, said article have been withdrawn later by the publisher, and CCTV isn't a particularly reliable news source (they have faked an exposé on shredded cardboard 'pork' buns before), and the Chinese government measures are probably makework (of course, some reforms were also necessary and the whole furor provided a good opportunity to do so) just to allay concerns from the public, so, uh, prolly fake. I also doubt you can make soy sauce (at least, anything that would taste like soy sauce) out of just human hair.
(Chinese industrial practices are probably still rather... terrible, even with recent improvements)
That said, L-cysteine (an amino acid) is a common food additive (especially in bread products), and most (~90%) L-cysteine in the industry is produced* from hair or feathers ('safely', of course, unlike the exaggerated devil may care attitude portrayed in CCTV), even if it's food grade (a small fraction is made via bacterial fermentation, and an even smaller via direct synthesis), and in pure form it's a white crystalline powder (similar to some of the descriptions in the CCTV video). Even the FDA itself considers it safe when used at suggested levels as a bread conditioner (it can form sulfur crosslinks to make the dough more elastic). You can even buy it in bakery stores. I guess you could... conceivably use cysteine to supplement the microbial starter if the microbes used for fermentation need it? (don't think regular A. oryzae needs more though). More likely it's probably used to dope low-quality (likely acid-hydrolyzed instead of fermented) soy sauce with cysteine so that it can pass some quality tests, like how some Chinese factories did with milk and melamine. Unlike the melamine case though, using L-cysteine this way would sort of be 'safe' and be technically legal (at least until China banned all hair products completely in soy sauce). Sort of 'safe', that is, because this certainly isn't an intended or accepted use of the product, so even if the L-cysteine is food grade there still might be some side effects from potential contaminants (or just an overly high concentration of L-cysteine) if they use too much of it.
(*My knowledge of this specific industry practice may be slightly outdated, so maybe there are more L-cysteine sourced from microbial and synthetic sources nowadays.)
...but yes, if you've been eating commercially-produced bread, it likely has added L-cysteine in it, and if it isn't like one of the slightly fancy-schmancy brands that take care to source their L-cysteine only from bacterial/plant sources, well, I guess you technically have been eating something made from human hair, but only a trace amount. Shouldn't be a problem though, as icky as it sounds.
Just to add onto this, just keep in mind that The Law of Conservation of Energy and Matter basically means that nearly every atom of every cell in your body has probably been inside of another living creature's body at some point. All H20 molecules are the same, even if one was freshly minted in a fuel cell from pure oxygen and hydrogen, or if they've been in the pee of a million different fish. If you're chemically altering something enough, you can't really call it that thing anymore, just as much as if you buried your dog in the backyard, the body decomposed, a tree grew partially on that decomposed matter, and then you chopped down that tree and made a table from that tree. Yeah, it's technically some of the same atoms, but it's not like you're setting your coffee mug down on Fido anymore. It's really only a matter of whether all impurities have been removed, not what had to be removed.
This in particular applies to complaints about "toilet to tap" water purification (I.E. purifying sewer water back into potable water), since after all, ALL water has fish pee in it until it's purified. If it's purified back up to drinkable levels, it's safe to drink, no matter what was in that water before then, and it's not like any other water magically appeared from nowhere that never once touched another organic creature.
Much of what gets quoted in that Snopes article is a bunch of sensationalist noise meant to shock, but you have to ask if there's even a point in a company trying to stuff its food with "condom-filled hair"? Generally speaking, making anything out of any part of a human is going to be more costly than just using a livestock animal to start with - there's plenty of cow hair to go around at the slaughterhouse, too, after all, and you don't need to pay people to take the condoms out of the cow hair - so using human by-product is often not even the cheapest way to make a cheap filler. Likewise, it's not like you can just make food out of hair, you're breaking it down into a different chemical, which then is used as a catalyst in another chemical reaction, which is a process VERY far removed from just eating something straight. (Which is why most people probably laugh off the notion that "soy sauce is human hair!" immediately - you just can't make soy sauce directly from human hair any more than you can make it from old hubcaps, you're just not using the right chemicals to get there.)
Wait! However you look at it, isn't that terrible!?
Sumireko! Are you okay!?
*SPLURT*
Even the hair can be used for soy!
Thank God! Mokou! Help meee—!
*FREEZE*
I mean, you can make soup stock from the bones! "No part of the human is to be wasted!"