They truly do. And it doesn't even have to be many spammers, it only really takes one person to ruin a free service. I've had plenty of personal projects I had to shut down due to some random person who just decided to hammer my servers for no reasons. I block the IP or IP block and they get more. I put Captcha (HN always complains about it but this is why it's often needed...), and users (who pay nothing) complain that it's annoying. Running free services on the internet is truly a PITA.