CBP took my phone. Will I get it back?

I was travelling in the car from Mexico. I'm a u.s citizen. I gave my passport and they asked me if I had cash and if I brought anything. Normal questions. Next thing I am asked to drive thru an x ray and next thing I am sent to a detention room. I was kept there for four hours or four and half. Literally no questions or explaination for why I am detained. Was asked for my phone. They said …

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