"Trolling is a art" is perhaps the definitive statement regarding trolling. If we define trolling as the intentional disruption of another's emotional well being, often through a feigned promotion of an unpopular belief, or political position, the statement is in itself a troll. The deliberate use of "a" where "an" should be is likely to arouse a negative reaction among those concerned with correct english usage. The fact that the statement is itself directly referring to trolling and the art thereof gives further power to its effect; if you're jimmies are rustled by this statement, its author has succeeded, and its veracity has been confirmed.
jimbob: you're balls are lo thus as a small mammal.
fred:You fucking faggot, you meant "your."
jimbob: Trolling is a art.
fred: I think you meant "an." Jesus. English motherfucker, do you speak it?
An insult which does not require you to swear but destroys your opponent. This insult enlightens your opponent about their shortcomings and annoyance to the society.
Scanning fine art at work is completely normal. I am currently scanning fine art as I write this. My favourite place to scan fine art is in public places such as movie theatres and playgrounds.