Mugging
From Wittypedia
It has been noted by extensive research in the Wittypedia office that Tea only tastes good when it is served in a mug.Mugging is the worst crime known to mankind.
"Mugs of tea are the essential power source of every proffession from builder to bodger to office jerk and social work."
Stealing, borrowing, "i was just using it and was going to put it back"-ings, lending, duplication or cleaning are outlawed!
Precautionary Measures
Mugs should be acceptably dirty to the owner and dirty enough to keep mug theifs away.
The dirt seen on a decent tea mug (like your grandad uses) is not dirt. This tanned, stained interior is the work of the tea drinker and a prized reward and status symbol.
The stain not only contributes to flavour but the tarnishing can leave a mug with quite a price on the black (or very dark brown) market.
Taking tea intravenously is a common soloution to many workers in todays high paced world, but even those people should secure a good mug of tea every half hour or so to keep their levels up to the standard our grandparents have set us.
Final Note
Lets work together. People need tea it is essential to life. No more muggings!
Take care of your mug and don't let your fingers wander towards another persons. Respect Tea, respect Mugs, Love your Mum.

