"I think it can be taken for granted that people on this site have an elevated sense of skepticism"
I disagree. Being a participant on this site implies that one has accepted some or all of the central premises of the community: that we can significantly improve our lives by thinking differently, that we should be willing to think and behave in ways that are very counter-intuitive to the average person, and that we can learn to do all of this by reading and talking on a website.
A great many 'normal' people would dismiss Less Wrong as a silly venture. Likewise, they'd be willing to dismiss something that looks like a scam immediately, without any thought at all. Those of us who pride ourselves on being clever, being willing to embrace an idea that other people would reject, and want to exploit loopholes and inefficiencies that other people have missed? I suspect we're less skeptical than the average person.
Being on the site only signals that we want to be rational, and like to think that we are. It doesn't necessarily mean that we're good at it.
Recently, multiple suspicious user accounts were created on Less Wrong. These accounts don't post any content in the forum. Instead, they are used only to send private messages to the existing users.
Many users have received a copy of the same message, but different variants exist, too. Here are the examples I know about. If you have received a different variant, please post it in a comment below this article:
I don't know yet about anyone who replied and got scammed, so this is all based on indirect evidence. If you got scammed, please tell me. If you are ashamed, I can publish your story anonymously. Your story could help other potential victims.
Most likely, the scheme is the following:
(Thanks to ChristianKl for explaining the system in the Open Thread.)
If you replied to the original message and now you are already in the middle of the process, please inform your bank as soon as possible! Even if the step 2 didn't happen yet, so you can still get out without losing money, warning your bank about the scammer could help other potential victims.
Warning: If you have already received a check or a payment confirmation, and someone is asking you to send the overpayment back quickly, do not send anything. The check or the payment confirmation is fake, and the goal is to make you send money before you find out. (Thanks to qsz for explaining.)