Over at the Times, Thomas Friedman has invoked his own slippery slope to argue that if we don’t allow the NSA to log our calls and finger our metadata, another 9/11 might encourage us to cede our civil liberties even worse. It is a pretty convoluted slope—call it the slippery water slide. Friedman’s essential claim is that, while this recently-revealed infringement on our privacy is bad, it does not have so significant an impact on our civil liberties as the theoretical laws a frightened populace might accept in the aftermath of another theoretical 9/11. Then we’d really be in trouble.