Customs has always been able to search everything without a warrant or suspicion when crossing the border. I guess this is saying that they can search the digital contents of physical devices/media as well?
It says they can manually search them. According to this, the ruling explicitly doesn’t say if they can digitally search them.
Not everything. From the case itself:
"To be sure, nonroutine searches, which are “more invasive searches, like strip searches, require reasonable suspicion.” Id. But we have held that “the label ‘non-routine’ should generally be reserved for intrusive border searches of the person (such as body-cavity searches or strip searches), not belongings.” United States v. Levy, 803 F.3d 120, 123 n.3 (2d Cir. 2015) (emphasis added)."