Of course we can’t……
Check it out:

Two weeks ago the FBI and Homeland Security released a memo warning Americans about lone-wolf terror attacks inside the United States. For months lawmakers have expressed concern about Americans fighting with ISIS overseas re-entering the U.S. using their passports, which according to the State Department, have not been revoked. According to Democrat Rep. Tim Bishop, at least 40 ISIS fighters have already returned and are being tracked by the FBI.

Now in an interview with 60 Minutes, FBI Director James Comey is warning an attack inside the U.S. from the Al Qaeda linked Khorosan group could happen “very very soon” and said that stopping Americans fighting with ISIS or other extremist groups in the middle east from coming home is pretty much impossible.