That's definitely junk they got using duplication (dupe) glitches. People have been duping all kinds of stuff since the game's release and many of the dupe methods surfaced over time. Some of these bugs were fixed, some people who used these glitches got banned (We got player vending system offline for two weeks already due to one of these bugs, devs still can't fix it so they just disabled the ability to use the vending machines for a time being), but with every new dupe fix people still find methods to duplicate stuff.