1) Audio salesmen disguised as end users on audio forums who are in fact only there to make a buck. We should start a list.......
2) Folks who don't know the difference between their opinion and fact (my opinion!). :-)
3) Shoddily made, yet well regarded, products. We could start a list.......
4) Dishonest sellers who sell on AGon and Ebay stuff that is giving off indications of impending failure as low use/like new when in fact it's neither.