Why is the TSA Scanning Paper?

I’ve been reading a bunch of anectotal reports that the TSA is starting to scan paper separately:

A KSHB Kansas City is reporting that other passengers traveling through MCI have also reported the paper-removal procedure at the airport. One person said that security dug through the suitcase for two "blocks" of Post-It Notes at the bottom.

Does anyone have any guesses as to why the TSA is doing this?

Source: Schneier on Security @ May 5, 2017 at 07:36AM