typo => better wording

sietch.tex

@@ -970,7 +970,7 @@ value a \zaddr likely has and how much funds pass thru it per time interval, as
 
 In summary, Shielded Coinbase was implemented by Electric Coin Company with no regard to increasing privacy on their
 blockchain. Since increased \zaddr usage does not translate into more profits, it does not seem likely that they
-will ever have meaningful privacy on Zcash mainnet. Only Zcash Protocol coin which enforce \zaddr usage have a
+will ever have meaningful privacy on Zcash mainnet. Only Zcash Protocol blockchains which enforce \zaddr usage have a
 chance at meaningful privacy.
 
 \nsection{Special Thanks}