Since SOCKS5 username and password are sent in plaintext, anyone in between can intercept and associate it with the traffic. The username given for proxy is almost the same as the one used for account login. Proxy traffic can potentially be associated with personal information, for example, users' billing details, in case of a data breach.

Therefore, it would be helpful to randomize proxy usernames, or allow traffic to/from PIA VPN use proxies without login.