Can happen anywhere , I knew 2 guys in the Bank one of whom was persona non grata but they could'nt fire him , he turned up for work every day and ran his antique business from his desk for years until they paid him off !Yes expense abuse happens in both private & public and we Irish are good at it.
One last example Complainer will love.
Govt dept employee, friend of mine - his primary duty is to answer a 'hotline' for members of the public and deal with the query. Problem is that the phone very rarely rings (average twice a month). Not my friend's fault. So what does he do? Fair play to him, he set up his own business/company and ran it from his office. Spent 2 years running his own business from within his public sector job. Then he left and concentrated solely on the new business. Better than sitting there bored reading the paper which others would do.
The other chap ran a bookies from from the branch - you probably remember the court case !!