user3292: Say a malicious mobile bitcoin client is created, programmed to quickly send two or more double-send transactions whenever a payment is made.  
Is this an attack vector we should be concerned of?
What could be done in order protect against such an attack?

user196: 
What could be done in order protect against such an attack?

Wait for N confirmations before accepting a payment as successful.

3292: <p>Say a malicious mobile bitcoin client is created, programmed to quickly send two or more double-send transactions whenever a payment is made.  </p>

<p>Is this an attack vector we should be concerned of?<br>
What could be done in order protect against such an attack?</p>
 196: <blockquote>
  <p>What could be done in order protect against such an attack?</p>
</blockquote>

<p>Wait for N confirmations before accepting a payment as successful.</p>
