[5.12] What should I do to someone who posts something off-topic?
An extended flame war against an off-topic posting is just as off-topic as the
original off-topic posting. The cure can be worse than the disease.
Instead use something brief and professional such as in the previous two FAQs
(which, by the way, were adapted from other sources; see the credits in those
FAQs). And please don't get personal or nasty — that just prolongs the
(off-topic) exchange.
Remember the 5 "B"s of correction: Be Brief Brother, Be Brief.