It hasn’t happened

“There never was a scheme against which objections might not be raised. But this alone is not a sufficient reason for rejection. The only line to judge truly upon, is, to draw out and admit all the objections which can fairly be made, and place against them all the contrary qualities, conveniences and advantages, then by striking a balance you come at the true character of any scheme, principle or position.” – Thomas Paine, “The American Crisis”