On: Stop Saying Bitcoin Transactions Aren’t Reversible

[vertex-four]

I've bought from the Humble Store twice recently, both transactions have been accepted instantly (i.e. before being included in the blockchain).

I don't believe that anyone's heard of a successful Bitcoin double-spend attack against a competent merchant yet.

[ars_technician → vertex-four]

That's because protection was added (about a year ago I think) to rapidly broadcast detected double-spends through the network. Before the canary function, it actually used to be pretty easy to get a double-spend accepted into the network within 5 minutes of the first spend.