Actually, my friend simply reverse engineered FedEx and UPS tracking numbers, then backtracked sequentially by ordering an iPhone every few weeks.

I say “simply” because it doesn’t require any of the infrastructure you mentioned, which is what the public typically associates with “alternative data.” It was actually quite impressive and novel at the time, and inspired other projects of mine.

I can talk about this now because (to my knowledge) it no longer works, though it did for a while. He was in charge of approximately $100M when he was working on this.