Brand Killer Robots reveal::
I once uncovered a group of people working inside a games company, who were steering the development of software towards their own personal objectives. "They were mean't to be developing a bespoke system in-house, but were using the time to create a commercial software product instead". These efforts were camouflaged in all sorts of ways, more especially so because they were ensuring they were seen to deliver functionality, albeit very slowly. "I was invited to take a look at this problem, to investigate why the project was now 100 days behind schedule." I analysed the context of their behaviour and approach and provided my report. This ring was monitored and then carefully broken up.
Recommendation: Monitor relationships between fellow software developers. Ensure reporting of project status is regular and software progress is audited. Ensure code controls are in place and security policy is adhered to at all times. Ensure product work is conducted such that dependancy on one or many developers is not high.