When using the hr_holidays module, any leave events created automatically generate calendar meetings, which is great for using the calendar to see who is off and why. The problem is anyone can edit or delete those calendar meetings; this doesn't change the actual recorded leaves but it makes the calendar view useless. I've tried setting all the calendar events I can find to read-only under Security->Access Control Lists but HR Employees can still edit or delete the events.  Does anyone know of a way to make them read-only?  Thanks!