Building, patios, etc. The rate at which it is being half inches was getting excessive, vastly outstripping the rate at which nature was replacing it. The Sardinian authorities tried the softly softly approach but people took the wee wee, so they've had no choice but to crack down severely. It's been massively publicised - it was on the news here a few months ago - so they've got no excuse.
They took a chance and got caught, so I've no sympathy with them paying for the crime. If they think saving 50 quid on buying sand from a legitimate source is worth the risk of a few years in the chokey then that's their problem.