Thousands of Foreigners Got Visas Revoked for “Terror Concerns”… Where are They Now?

While President Obama assures citizens that there is no “specific and credible threat” of terror against the United States so far this holiday season, the feds can’t seem to find thousands of undocumented foreigners on US soil who have had their visas revoked amid terror concerns.
The Obama administration cannot be sure of the whereabouts of thousands of foreigners in the U.S. who had their visas revoked over terror concerns and other reasons, a State Department official acknowledged Thursday. The admission, made at a House oversight hearing examining immigrant vetting in the wake of major terror attacks, drew a sharp rebuke from the committee chairman.
“You don’t have a clue do you?” Rep. Jason Chaffetz, R-Utah, told Michele Thoren Bond, assistant secretary for the Bureau of Consular Affairs.
… “I don’t know,” she said
It is worth noting that one of the San Bernardino shooters entered the United States using a K-1 fiancee visa.
How could this be? How could the feds be so effective at identifying conservative groups and targeting them through the IRS, but can’t seem to identify and remove individuals whose visas have been revoked for terror concerns?
If the government is too incompetent to track down potentially dangerous individuals in the United States, then they need to be more rigorously vetting those individuals before they enter the country in the first place.
The stakes are too high to be incompetent at both things.