What is Ad Hominem?
1.
An attack upon an opponent in order to discredit their arguement or opinion. Ad hominems are used by immature and/or unintelligent people because they are unable to counter their opponent using logic and intelligence.
Person A: I think we should spend more money on environmental protection.
Person B: You just think that because you’re a stupid tree-hugger.
Person A: It is crucial that we facilitate adequate means to prevent degradation that would jeopardize the project.
Person B: You think that just because you use big words makes you sound smart? Shut up you loser; you don't know what you're talking about.
2.
Whilst in an arguement, to avoid the point (thus a cop-out) and to insult the person arguing. Often because the person who results to the insults has no logical/intelligent point, thus they break down to immaturity.
Jon: I've made my point five times and all you've done is call me 'gay', way to resort to ad hominem, dude.
See
3.
Originally from the Latin meaning - "argument to the man", "argument against the man".
Now meaning Argument against what a person has posted via the net and brought about by Psychological projection as to the person hidden behind the Computer Screen and On-line Identity.
Can also be seen as an idiotic lack of appreciation of Netiquette and also gross self absorption by the reader/responder.
"Dear @$£*&% I read your post and am shocked by the Ad Hominem way you respond to reasonable dialog in this forum.... etc etc."
See