This question reminded me of a story I read in the 90s.
A woman is caught shoplifting a bunch of metal items by throwing them into her purse. She has no memory, and the purse is empty. Anything metal they put in disappears. The police turn it over to government scientists, who investigate by attaching a large lump of metal to some extremely strong wire and dropping it in like a fishing line.
They have it hooked up to the biggest, strongest crane available, and they begin reeling it back in. They reason that if whoever is on the other side can't let go, it could turn their universe inside out or something equally unpleasant, thus giving Earth the leg up in opening negotiations.
and then
The tension on the line increases until is under too much tension to cut. The story ends with the line slowly sliding back into the purse, with the realization that their plan has backfired in the worst possible way.
Anyone know the name of the story and author?