The 9th circuit has jurisdiction in this case because it happened in California. US v. Cotterman is the relevant case, and the 4th circuit made a similar ruling in US v. Kolsuz, but the 11th circuit held differently in US v. Touset.

So in some parts of the US, reasonable suspicion is required. In some parts, it isn't. In some parts, there is no binding precedent on the issue. It's likely that the supreme court will hear a case on the issue eventually.