Not an AIBU, but this is the board where you see it most often.
Sometimes it's because the OP posts about a small incident in their relationship with someone else, often a DH/DP. The first posters say that she's being unfair and controlling, then someone comes on and says it might seem trivial, but in the context of the OP's other threads it's not, it's part of a bigger picture of abuse by the partner.
Other times the OP's scenario is completely outlandish, the first posters agree that the OP is not BU in the slightest, then someone says it's strange but the OP seems to have a lot of other threads where the situation equally stretches credibility.
How do you do it? Do you pay close attention to user names, or is it something else? it's very rare I can spot them.