Janet Napolitano said last month that we should expect to soon see tighter restrictions at bus, train, and marine transportation centers, too. Here's a report about TSA, Border Patrol, and local police setting up a checkpoint at a Greyhound station in Tampa. Note how quickly preventing a possible terrorist attack expands to include catching illegal immigrants, and preventing drug and what sounds like "cash smuggling." (It's hard to tell from the audio.) Note also the complete and utter reverence the local news report bestows on these government agencies, who after all are merely "teaming up to keep your family safe."

A liberal blogger wrote to me in an email this week that libertarians who call the TSA pat-downs a violation of their civil liberties do a disservice to actual violations of civil liberties. It's not difficult to envision the day where anyone wishing to take mass transportation in this country will have to first submit to a government checkpoint, show ID, and answer questions about any excess cash, prescription medication, or any other items in his possession the government deems suspicious. If and when that happens, freedom of movement will essentially be dead. But it won't happen overnight. It'll happen incrementally. And each increment will, when taken in isolation, appear to some to be perfectly reasonable.