The 38% true positive rate makes me think that either border customs violations are incredibly broad and common, or there is some kind of parallel construction

The 38% true positive rate makes me think that either border customs violations are incredibly broad and common, or there is some kind of parallel construction happening here where they have a good idea of what they hope to find when they seize these devices from extralegal sources. Edit: given the source, the 38% could also be inflated (perhaps by not counting certain false positives) since it comes from the department looking to justify their work.