as far as i know radio-app deals with external links and sites (“This experimental app uses the radio-browser.info api”) so it could be that some of those got compromised… (for me it reads like a personal flaming that has gone too far and too personal for which reason ever).
what that means in terms of YOUR instance, i can’t tell. at first guess it means that your instance hasn’t neccessarily been compromised as well. but what would happen if you’d click on links? at least: be careful.
i’m pretty sure there are other peeps here able to answer more precisely.