Horray for human beings who can manually exclude, amirite?

Asians do use stuff like "ydm560468486" as login on websites as a habit, as they see it as a code more than an actual username.

(sometimes, not always)

Theres a constant churn of spambots that try to post to nearly everything. I guess the logic is that the admin might make it hard to tell what the thing is, so they just try a bunch of common methods of posting then move on.

~ That guy who supports Web Application Firewalls

Could be
I would just delete it.

That or someone keep putting in there FA Password and not there username, i can see how someone can make that mistake