Been there. Remember getting a call from a data center I'd never heard of asking to speak to the old sysadmin who'd quit 18 month ago. They asked something about the rack of servers we had in their data center, I replied "what rack? what data center?" Turns out that 2-3 years previous the old sysadmin had set up a dozen servers in their data center for some project (that I'd never heard of) that very shortly afterwards first got pushed forwards and then canceled. Everybody involved in that project promptly moved on to other things and no remembered to cancel the deal with the data center. So for two years we'd been paying quite a lot of money to keep a completely idle rack of pretty expensive servers and apparently no one noticed.