[tialaramex]

Maybe. It can probably use this to help the user who uploaded it do something, since for that purpose it's evidently suitable - if I upload the claim that rypskar has the nickname "Dog boy", their phone number is [phone] but they live in New Zealand, then providing that information back to me seems pretty harmless even if it is bogus.

But if they take this data and then try to do something else with it, whether that's contact rypskar or give the data about rypskar to somebody else - that's going to run into lots of GDPR problems around correctness (the data processor is obliged to take reasonable steps to ensure the data is accurate and fix problems on request) and as you identified with permissions (did rypskar authorise this? How do we know? Who even is rypskar?)