My daughter connected in ORD about a week ago on her way home after a 5-day trip. She had about 50 bags of frozen breast milk. TSO told her she could not bring all the bags with her through security. She told him that he was wrong. He then said she'd have to open every bag and allow them to test each one for explosives. She told him no, as her arriving flight had arrived late and she was in danger of missing the next flight.
TSO finally obtained a supervisor, who didn't seem to know what to do. The TSO asked the supervisor, 'what are the rules?' (imagine that: the TSO does not know the rules, and even more strangely, thinks there are rules!) After some hemming and hawing, the supervisor said she had to open four bags for testing. (This is not the TSA's rule of course!)
Then the TSO wanted to physically dip the test strip into each bag. My daughter refused to allow that. However the TSO and supervisor said she had no choice. So after testing she threw away the opened bags that had been contaminated by the test strips.
This process by the TSA is completely out of control. Nonsensical... illogical... illegal... and so on. She (and I) were very angry about another "fine" example of the TSA's "making us safe."
Contact the ACLU and local media. File a complaint against the screeners with the DHS OIG.