The exact definition of secure anonymous proxies is difficult to decipher. A vital point to remember is that adding tags to proxy server description doesn't affect the server effectiveness.
Take the case of one of the basic premises of running anonymous, secure proxy server. The worst thing one can do is to run proxy service as roots. There are many configured that way.
The main problem is that any bug, vulnerability or flaw with ordinary proxy servers causes the entire machine to get compromised.
Root account provides complete control of the server, web traffic, the logs and the browsing sent through the proxy. Though it appears stupid, users may find various anonymous proxies, appearing on the net and configured by way of root account.
There are common alternative, running in the user's content. These are better, especially as the account lacks privileges, putting the server at risk.
However, it isn't a suitable configuration for high anonymous proxies. The main reason for this is that the account contains write and read privileges over directories and public areas.
It also contains rights over the logs created in context user, which means all proxy users have potential access to the files and logs created by user.
Terms and Conditions
The user account shouldn't have any other access rights whatsoever, including each proxy session that runs in the individual user's context. This protects the anonymity and security of proxy users, securing their files and logs from other surfers' using proxy service.
Anonymous proxy configuration is highly vital, insecure and badly configured which places information and users at risk. Always remember - while using proxy server, create a single log of browsing using the ISP logs. If it is insecure, you put the security at high risk, more than when not using a proxy.