When you hear the Homeland Security folks saying that they're tightening the standards for travelers this week, in the aftermath of the failed bomb attempt on a Northwest Airlines flight last Friday (Christmas Day) from Amsterdam to Detroit, they aren't kidding.
A member of my family was traveling back to the United States from China on Monday, via United Airlines, and apparently there wasn't a problem leaving Beijing. She had nearly a three-hour layover in San Francisco before continuing on another flight to Denver, which seemed to be far more than enough.
It wasn't. After waiting for baggage, going through customs, re-submitting the bags for the domestic flight, then going through an additional security screening, she barely made that flight out of San Francisco in time.
So don't be surprised if anyone you know has to deal with customs returning from another country, especially now with the added layers of security. Most likely, it'll mean a lot more travelers missing their connections and having to (hopefully) catch later flights.