It is a strange issue to hash out when a uniformed BP/CBP officer is physically blocking a line to the TDC. On the one hand, if I said I don't want to answer any questions and s/he moved aside, that would be fine . . . for me.

On the other hand, you have people (call them "kettles" for the time being) who walk up to a line to go through security. They see people with DHS patches and badges and other people with DHS patches and badges further down. They know that they have to show their boarding pass and ID to the people with the DHS patches and badges to go to through the security checkpoint if they want to fly that day, but are they expected to know the difference between the two patches/badges? Kettles would also expect that the questions they are being asked by all these DHS patched and badged folks have to do with airport security and would answer them.

I don't think the legality of such operations need be questioned for this reason (others can disagree with this, but I just don't see an issue), but this seems to be a case of real LEOs using the perception of authority that TSOs are given in order to further their LEO mission. It is truly the unique case when being perceived as a TSO rather than an LEO serves an LEO's interests!