Even with sign up there are ways to get around it by creating multiple accounts, so good luck getting even close without sign up AND without fingerprinting. At

Even with sign up there are ways to get around it by creating multiple accounts, so good luck getting even close without sign up AND without fingerprinting. At the same time you might get more false positives the harder you try, e.g. IP addresses can be legitimately shared between users while the ones trying to get around your limits know how to change theirs