The bitcoin ledger is a public record of every single transaction that's happened since a coin was mined. It is the exact opposite of private. That isn't a "flaw" per se, it's just the way it works. The way you prove you own a coin so you can spend it is by proving via the ledger that it was transferred from the miner through some number of intermediate owners to you.
In that respect bitcoin is much worse for high profile crime than cash is.
