Earlier quoted context omitted.
Yes, this is really little different from shutting down a whole forum because you received a single DMCA request. If anything it's even more of an overreaction, because a DMCA request could be followed up by legal action, whereas a data subject can't sue. All they can do is report you to the regulator. The regulator is unlikely to do anything if it's a frivolous request. Even if it's legitimate, their first action th…
DMCA is capped at what, $30k per violation? There are obvious ways to avoid it, and the law has settled down. GDPR is capped at $20+ million, no one knows what a typical fine looks like, the law is much harder to read, and everyone is afraid to be made an example of.
The EU has had data protection law for twenty years. The EU has enshrined proportionality of penalty in all EU law as a fundamental right. There is plenty of case law at the CJEU defining this.
All you need do is read the FAQs that EU ICO's have been putting up. The UK has never, in 20 years, applied the full penalty of the previous DPD, and under 0.1% of all reports got any fine at all.
A "typical" penalty will be help to comply. Perhaps a strongly worded letter.