Often my Jr & Sr's help out in the main service running ProPresenter for song lyrics. In that case they are supervised by the other adults in the tech area.
If I have my macbook in the youth room, I have it on a guest account with full tracking, even if I am the one using it.
In our line of work, there is often too many sensitive items that could damage a student or your own credibility if it were leaked. I'm not saying to be secretive, but be mindful of who information is released to.
If an elder or my lead pastor requests it, they get full access to my computer at any time.
I don't let my youth update our website, but Tim Schmoyer has some cool things about using twitter at the link below