The point is not that you can&#x27;t trust your results, it&#x27;s that you can&#x27;t extrapolate a theory about <i>all</i> toy bricks unless you know you are seeing a representative sample of all bricks.<p>&quot;I&#x27;ve run 10,000 experiments that show toy bricks <i>I found on the ground</i> are green, therefore I can say with great confidence that all toy bricks are green.&quot;  What about bricks in the toy chest?  What if someone was building something green before you tested?<p>As this applies to Facebook&#x27;s statement, all they can assert is that they&#x27;ve found a way to detect fake Facebook accounts that they&#x27;ve tested against the accounts they&#x27;ve been able to ascertain are fake.  What about the fake accounts they could not confirm were fake, or that weren&#x27;t identified in any way?