I am not too familiar with how Brave and BAT (Brave Attention Token), so please chime in. Here's how Brave describes the BAT YouTube donations system: https://basicattentiontoken.org/brave-expands-basic-attentio...
From my understanding, users of the Brave Browser select which YouTubers to donate to, but they don't know whether the channels have opted in to receive donations? What does Brave do with unclaimed donations? Someone pointed out this concern in an earlier submission: https://news.ycombinator.com/item?id=15730661
Furthermore, OP said that they might not be following GDPR due to collection of YouTuber data (to assign donations). IANAL, anyone know how compliant this is?