Good observation. And then they just check off to get replies by email, so they can just hit and run.
Disabling the "connect with <insert social media network" feature on the forums would probably eliminate most of these types of posts. Based on post count and usernames, I imagine these class of users are doing a quick Google search, connecting to the forum via one of the search returns and blindly hitting the "connect with facebook/g+/etc" button and posting a "PLZ HELP" reply without reading a single thing. If registration even requires a teeny bit of effort, chances are the lazier people will take the extra 5 minutes to read instead of having to manually register.