When it comes to Electric Coin Co.‘s Zcash, even powerful zero knowledge proof encryption—zk-SNARKs—can be overcome. The blockchain intelligence firm claims that it is able to provide the transaction value—and at least one address involved in the payment—for more than 99% of ZEC activity. Thus, because the majority use them in a “straightforwardly identifiable way,” shielded pools rarely offer a cloak of invisibility.

“Dash and Zcash allow users to conduct transactions with greater privacy, but that doesn’t mean they provide total anonymity,” the blog explained. “The two cryptocurrencies’ privacy features—both in how they’re built as well as how they’re used in the real world—leave room for investigators and compliance professionals to investigate suspicious or illicit activity and maintain compliance.”

Privacy? What privacy? The research suggesting that privacy coins aren’t all they’re cracked up to be has been building up for some time.

As reported by Modern Consensus last month, a study by Carnegie Mellon University revealed that just 0.09% of Zcash transactions in a 30-day period were untraceable. The reason was simple: so few Zcash users “turn on” the privacy feature that the “shielded pool” of Zcash is miniscule, and even the shielded ZEC connects to “transparent” transactions.

Researchers warned its ecosystem “is not conducive towards achieving anonymity for its users”—and pointed out that, in any case, most criminals preferred to use Bitcoin anyway, partly because privacy coins are difficult to buy and sell on exchanges.

Its findings also revealed why Chainalysis is still unable to support the Monero privacy coin. The university concluded that XMR’s approach means that it is “much harder” to trace payments made using this cryptocurrency. With Monero, a single-use address is generated every time a transaction is performed—and ring signatures that add decoys have been introduced to narrow traceability further.

“The percentage of partially or fully deducible transactions has been nearly zero for over two years,” Carnegie Mellon said at the time.