Isn't possible actually.
Being an ass 95% of the time.
There have been previous glitches before where it has been possible (or it was either fake when I watched them) or they are just visual tricks people do.
If you're annoying, you're on my shit list.
If you're a troll, you're on my shit list.
If you fail grammar, you're on my shit list.
If you're disobedient, a rule breaker or just a rebel at all, you're on my shit list.
Steam accounts have been banned in the past as a result of taking advantage of a TF2 bug where duplicating items is made possible. Most level 1 and 7 Max's Severed Heads are duplicated, and are therefore worth far less than that of any other level.
It has been done, but shouldn't be done. If you find a way to duplicate items, report the bug to Valve and you just might get rewarded for doing so.