California is in the grip of a historic four-year-long drought, and the most populous state in the US is seriously low on water.
Water wasters are being fined and sent to so-called 'water schools' to learn about the finer points of water conservation, sales of fake grass are booming, and people have even started spray-painting their lawns green.
It's not just city and state authorities enforcing water restrictions either; people power is playing a part too.
Waste water in your garden or at your school and Tony Corcoran and his smartphone might just be paying you a visit too. Mr Corcoran is on a one-man crusade to film, name and shame Californian water wasters online and via his YouTube and Twitter accounts.
Not everyone likes what he's doing though; he's been insulted, threatened and even sprayed with a hose!