@manankanchu @jtb @404mediaco Which is very common practice worldwide - exact timelines vary, but in general it gets stored for quite some time. If you want your payments to be as invisible as possible, you find methods that cannot be directly traced to you. Mailing money, using a prepaid gift card, or cryptocoin via multiple layers of abstraction to make it hard to trace who each transaction involves.
This is a reminder of what data can and cannot be accessed. Proton might not be able to hand over the direct contents of your emails and whatnot, but data like this can be handed over if required.