A specific phrase in the official documentation "Permitted and Prohibited Items" linked from the TSA site from a couple of the articles (to avoid possible legal problems?): http://www.tsa.gov/interweb/assetlibrary/Permitted_Prohibited_5_16_2005_v3.pdf and here: simply to ensure one copy is available.
"The prohibited and permitted items chart is not intended to be all-inclusive and is updated as necessary. To ensure everyone's security, the screener may determine that an item not on the prohibited items chart is prohibited [*1]. In addition, the screener may also determine that an item on the permitted chart is dangerous and therefore may not be brought through the security checkpoint [*2]."
[*1] N.B. note that the wording does not
require explicitly that the item be necessarily a threat to security, only
that it becomes instantly prohibited...
So it doesn't really matter whether something is accidentally or intentionally brought to the security checkpoint, only whether the screener considers that the object could be a threat or not... Guidelines are provided, but screeners have no obligation to be held by them? When do we start seeing minimum quotas for fine-based revenue to justify the presence of the screeners?
Sent to Jerry Pournelle's original blog by James Siddall jr.
And, see another side of USA border controllers concerning the chain-saw