It can’t. It tries to hide what a zero-knowledge proof never reveals in the first instance. And really, anybody who believes a mix scheme be more private than a zero-knowledge proof must be under the influence. Hmmm.
The Monero troll attacks against Zcash follow a quite familiar pattern, well-known to anybody who has ever read a gentleman’s guide to manipulation of social media. In certain venues which dominate popular attention, persons who evidently have 25 hours per day of free time suddenly flood every thread with anti-Zcash screeds which make up in volume and emotion for what they lack in substance. Conveniently, some of them also openly express how well the “plausible deniability” of Monero’s minuscule anonymity sets will ostensibly get you off the hook before a jury (!).
Zcash bigwigs rarely reply to such attacks. Perhaps they are just too busy to Argue On The Internet. But also conveniently, they occasionally say something which sounds friendly to “law enforcement”. This makes Zcash anathema to anybody who has a pathological blind hatred of the policeespecially when such statements are endlessly repeated by Monero shills.
As late as the 1980s, Swiss banks still had excellent privacy. But they did not want dirty money. They didn’t care if you had kept up all the paperwork demanded by the bureaucrats in your home jurisdiction. They didn’t want to know about that; that was none of their business! But if, say, you were a drug dealer, they did not want your business. So, legitimately rich people stashed their private coins in SwitZerland; while drug dealers paid outrageous percentages off the top to attempt laundering their money, not always successfully.
Conclusions are left as an exercise to any reader who has studied how to build privacy-enhancing technologies, and defend them against the “social attack”. This is a people problem, not a technical problem; thus it has a people solution, not a technical solution.
Aside, I have a pet hunch that the bubble in June was a deliberate maneuver by a high-cap market maker to shear the idiots who bought Zcash high (so to speak) for prospective illegal use. They won’t be back, and good riddance.
Note, I myself have had some reservations about Zcash unlinkability. Other criticisms, too. I’m not married to it. But it should say enough that most of my (small) worldly wealth is currently locked up in the global anonymity set of note commitments.
At the bottom line, people: Please let the Monero trolls do their thing, and drive the artificially addle-brained to use Monero in their “markets”. Ignore them, and save Zcash for smart people who just want some privacy. That is defending the ZEC. Thanks.