[nextgens]

Yes, we're talking about an attack against the zipper (and not the zip tie nor the bag)

The goal here is tamper evidence... sure you can open the bag through the zipper but you won't be able to close the zipper back if you can't move the sliders.

[bradknowles]

I dunno, I think something like [1] could do a pretty good job of putting the zipper back together and then you would just have to remove the underside component at the very end and then jiggle the existing zippers to hide the fact that it had ever been opened that way.

I suspect there might be even more surreptitious versions of such tools.

[1] https://guide.sportsmansguide.com/tips/camping-101-quick-fix...

[nextgens]

Sure you can defeat it using specialized tools... but at that point, you are far from "all I need is a pen" and opportunistic attacks. The tool will have to match the width of the zipper: you'll need a collection or to have done reconnaissance.

At that point, shimming the zip-tie itself is probably easier/faster (and doable without specialized tools).