it’s not sketchy, it’s basically a captcha to keep down automated bot sign ups, and they link to that document in particular, i assume, because the devs are marxists and figure folks who are vehemently anti-communist would refuse and thus keep down their moderation load.

generally, a serial killer does multiple individual murderers over an extended period. this contrasts with a mass murderer, who kills a bunch of people in a single event, or a spree killer who does multiple killings over a short time span. a serial killer may take a couple years to kill 5 people while a spree killer does it in a weekend, and a mass killer manages it in a few minutes.

but then we wouldn’t get to see the pretty boat!