Can the users of a messaging group ask under GDPR the owners of the group remove them? Then rejoin to repeat (it leads to more processing of their data) if the messaging service provides a "leave button".
Article 12(5) of the GDPR allows a refusal or the demand of a fee for requests which are "excessive, in particular because of their repetitive character".
I would suggest that before you demand such a fee, you should consult a lawyer in your jurisdiction about the details. How many requests are repetitive?
Also note that the GDPR usually does not give the right to be removed from a group. It allows the right to have any data deleted if there is no other legal reason to keep it. That's a different action. Pushing the button might not immeditately delete old data.
However, under Article 12
Information provided under Articles 13 and 14 and any communication and any actions taken under Articles 15 to 22 and 34 shall be provided free of charge. Where requests from a data subject are manifestly unfounded or excessive, in particular because of their repetitive character, the controller may either:
- charge a reasonable fee taking into account the administrative costs of providing the information or communication or taking the action requested; or
- refuse to act on the request.
The controller shall bear the burden of demonstrating the manifestly unfounded or excessive character of the request.