I heard that EU food delivery apps was frauded this way: customer installs app, get hefty first delivery discount, asks to delete their data due to GDPR, rinse.

I heard that EU food delivery apps was frauded this way: customer installs app, get hefty first delivery discount, asks to delete their data due to GDPR, rinse. repeat. They figured that out by keeping a hash of their phone number for some time like 3 months and not giving a discount to those numbers.