You will instantly spot blocking because apt reports connection failure and hash failure and replay attack on update list is ineffective. As for privacy, eh? I

You will instantly spot blocking because apt reports connection failure and hash failure and replay attack on update list is ineffective. As for privacy, eh? It is visible you're connecting to a debian mirror and what size of update list you're getting. Barring that, indexing packages by size is trivial. You want true privacy, you'd have to use Tor or such.