Homeland Security under the Obama Administration.
There are signs posted at the entrances to all Federal ports. Upon leaving or entering the United States all persons and conveyances are subject to search. If you don’t want to be searched do not set foot on Federal port property. I am not saying that is good or bad. Plan ahead.
This goes further back than Obama, even prior to 9/11 before DHS came about border officials have had the law behind them to do whatever they choose to do. Most of the time they don’t press the envelope but it is there for them and has been for a long time. Before Customs came under Homeland Security they were under Treasury and had extraordinary legal leeway especially at the border even then.
Considering who she is and what she does I imagine the rest of the story is she was likely flagged in the computer for contacts she has that DHS is interested in. Possibly rightfully so. Some supervisor just decided not to press the issue so she was allowed to go her merry way.
If anything Obama being in charge likely is the reason her phones weren’t taken at least for a look through. His idea is no border security.