If an intern did it (or even a low paid full-time employee), one could easily turn a profit selling used equipment. (I work in the refurb department, reselling used stuff is literally my job!) 5 minutes per monitor @ $25/each = $300 per hour. You could sell to wholesalers for much less per unit, in exchange for not wasting time with random people.

I'm not sure how prevalent this practice is, but IT equipment is sometimes on a depreciation schedule. If an employee starts selling the company's PCs and monitors, an accountant will get very angry, because he told the government that the stuff is literally worthless, but it apparently isn't because it was sold for something. IANAL, but I'm fairly sure that's tax fraud. Once it's turned over to someone else (my company) for free, the valuation resets, or something.