This is a quote from the book "On Zero Confirmation Transactions" by Chris Pacia
...from including them in blocks, but it deletes them from memory allowing double spends to take their place.

So a new attack would look like this: Create two transactions; One sending
coins to the merchant with a second output sending a small amount of coins to a gambling service. Then create a normal double spend transaction. Send the first transaction to the merchant, walk out the store with the merchandise, then send the double spend to the Eligius pool. At the time of writing Eligius has about 3% of the hashing power. That means you have a 3% chance that Eligiu...
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