In the Internet as role playing game conceptual metaphor, orcs are unruly participants who are not as powerful as trolls. If they had the power to be trolls, they would be - their intent is more or less the same, to twist a poorly-managed systemic bias in their own favour. (See Project Crankshaft)

By comparison to trolls, orcs are those who employ inefficient methods such as joining the sysop power structure or other power structure, fawning and wheedling for infrastructure owners trust, usually so they can engage in ad hominem delete - or other sysop vandalism, ad hominem revert, witchhunt including the more comical and futile wiki witchhunt, outing, libel, false police reports etc.. They often cross the line of what is legally or morally acceptable. Just as trolls thrive in a trolls nest, orcs thrive in a libel pit.

Very minor orcs or goblins simply gibber in fright and repeat nonsense that the orcs sputter to oppose the trolls in their constant power struggle, e.g. Tom Manley has been implicated as one of these in the GPC Council crisis.

Gremlins by contrast only cause accidental sabotage and gnomes are entirely uninvolved, tending a garden.

presently infesting

It has been suggested that certain web services and even whole NGO and political party structures have been infested by orcs.