Most large companies I've worked for require that you take one contiguous break of at least 2 weeks at some point during the year. Long enough that someone else will have to take over your day-to-day duties.
This is good for the employee (to have a proper holiday, and avoid the pressure of being the only one who can do something), and good for the company (it gives time for fraud and cover-ups to surface, and forces the spreading of information within the teams).
This is very interesting (and clever). Mind telling us more? :)
The idea of enforced contiguous vacation time is that this kind of fraud is revealed when at least someone else has to step in and fill in for the time the fraudster is away. Even if someone doesn't backfill the position during the vacation time, surrounding processes and controls are supposed to pick up evidence of the fraud now that the tampering cannot be engaged.
Basically, no one with control over finance and accounting functions is supposed to be so indispensible that they can only take a few days here and there off. In fact, someone in those roles that makes a big deal out of being able to be away for long is usually a red flag for auditors.