> After all, we know that SELinux breaks things, but it's being deployed. I would expect that SELinux has broken far more things than a handful of permission checks in X would.
Most SELinux permissions checks happen where applications should already expect them to be occurring such as on filesystem objects. Putting in permissions where there weren't any before and where there is a lot of backwards compatibility requirements for very old software seems like a very bad idea and quite likely to break the world.