As the music began for a third day at a music festival in northern California last Saturday morning, 38 people sat at a campsite nearby, sharing how they would get through the weekend without relapsing.

By Kamala Kelkar

California has ramped up the use of sobriety checkpoints to target intoxication and crack down on unlicensed drivers. But its policy of seizing vehicles is under fire both for targeting undocumented immigrants and for generating an estimated $40 million in…