With PHP you could use open_basedir to prevent this, but there are more ways. And with Python, Perl or CGI-scripts there is no easy way. Plus that users don't care if it is about security (unless you show them how easy it is), so there is a big dillema. And we didn't even talk about hidden bugs in almost every security measure we take. A knowledgeable person can almost certain find backdoors because of the vast amount of possibilities these scripting languages offer.  == The solution == Instead of wasting time to secure all the possible things you don't want as a webhoster and in the process frustrate your clients, it is far better, easier and more flexible to give every account its own environment. OpenVZ is ideal for this. In this article we describe how shared webhosting with OpenVZ could be implemented.