>disguised as thieves stealing fiber optic. This does not have any sense economically, as the value in the market is zero

Do you honestly think that crackheads think that far in advance?

I've seen fiberoptic cables stolen from 2 (city) jobsites in the last 5 years, once by tweakers later caught trying to sell them as scrap copper and the second thief was never caught. This happened even though the spools had big signs on them saying "Fiber Optic Cable - NO COPPER".

This used to happen more often in the past, when copper thieves mistook fiber for conductor. There were cases where critical systems were shut down due to fiber optic theft, and the thieves were caught burning the sheathing to expose the... glass.