An anonymous reader writes: What do people use on small-scale projects (non contractual) such as web sites and data processing scripts to ensure payment? I work almost exclusively with scripting languages such as Perl and Python and wonder if there is any "standard" way to obfuscate self-destruct routines that render the software useless after a short period of time. The method needs to be simple, yet not "easily" broken by your average office IT worker by simply editing out the code or resetting a system clock. Ideally, there would be something that after so many uses would lock out the code, followed up by a MD5 sum checker that would further lock it out if any changes were made to the target script. Any ideas?