Making a modal window
[J Arun Mani]
Look up kiosk instead of DM maybe?
[Gene/Brian] Yeah I find your surprise surprising...
All operating systems (except MSDOS!) have a detailed notion of protection levels, the basic point being that all users are NOT equal.
And OS progress happens when this notion is refined more and more. For example we have users and groups
then we have ACL and cgroups and other more modern zany stuff I don't understand pretend to understand!
All having the basic requirement (like the OP) that some users be prevented from doing some things that they very much would want to do
1 Try removing youtube from android
Phone and you will find it's not possible.
2 I used to teach computer science at the university. And at a time when a single large mini was shared by all there was this dilemma: Give students root access and have them learn about operating systems but putting other people's stuff at jeopardy. Or let them be ordinary users and not be able to try out things at the OS level.
3 Parent doesn't mind child breaking the computer but would not like child to visit certain websites