Re: "Can we actually trust any of the mega corps to remove the data"
You can selectively delete parts of those tables tho.
For example, there'd be a unique ID (a key) that us used to relate your customer identity details (name, address, DoB, etc etc) with the transactions. And any eBay transaction (bid, winning bid, etc) won't have your identity details in it, it will have the unique ID, the key, which is then used to pull out the identity details to list it with a purchase for example.
So while the TRANSACTIONS won't be deleted, or the keys (unique IDs), the data within the identity tables can be deleted (or replaced with NULL or a standard string like, "DELETED").
Therefore while all the transactions are still there (since they involve other people who might still want to know ID XYZ bought/sold the item), the individual identifying information can be deleted from a relational-based database (or any other for that matter), so rather than seeing "John Doe of 2343 Wanking Ave, Cayman Is. won the bid for Fleshlight", you'd see "345428946593 won the bid for Fleshlight".
Biting the hand that feeds IT
