Law enforcement agencies have been successful in the past in their attempts to connect an individual's» public wallet key with their identities. (cryptotaxprep.com)
The issue a lot of users have is that, if anyone knew Bob's public wallet address, for example, that person would also know that someone sent Bob 0.01 BTC. (finder.com)
On this basis the existence of private keys and encryption of said keys is particularly important and holding coins on a particular exchange's public wallet is not advised, as this could leave the coin holder exposed to cyber-theft. (fxempire.com)