stamagoy,
Since you didn’t say to whom you’re directing your post, that means it’s for everyone, some of whom are male, and some of whom are female. So whether you’re the brother or the sister, you’ve just violated your own rule!
Now, if you would tell me that since your comment is directed at nobody in particular, it’s impersonal and there’s no issue, I ask you: if you were in mixed company, would you be speaking up? No? Then you’ve just acknowledged the difference between anonymous chatting and non-anonymous chatting.
My opinion is that unlike non-anonymous chatting, which without a specific need is not appropriate, anonymous chatting is okay as long as the tone and content are okay.