University of Wisconsin researchers say getting it off your chest and getting it on line may be counterproductive.  They report that both reading rant sites and posting on them can bring on negative mood shifts.

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To find the effect they have on people, researchers surveyed 32-rant-site-users (such as JustRage.com and NotAlwaysRight.com) about their anger, their visitation habits, why they read other people's rants, and how rating made them feel.

The results-- people tend to rant because it makes them feel relaxed right after they do it. In a second, similar study, ranters said they felt sad after reading rants, and after writing rants they felt less happy and angrier. Apparently anything done with the intent of blowing off steam is counterproductive because it prolongs the amount of time you spend focusing on negative feelings. (Women's Health)