Originally Posted by bocastephen

It's extremely easy to "legally" overstay by exiting, even if they come up with these silly exit controls.

If you're here on a visa, book a cheap international flight you know is very lightly sold (so there won't be a pre-departure seat count). Don't check any bags, and make sure you do this well before your visa expires.

Check in, surrender your departure record to the airline agent, and go to the gate to board your flight. Board when the jetway and boarding area is crowded (affectionately known as the 'cattle call'), let them scan or collect your boarding pass, enter the jetway with everyone else, then quietly walk out - if no one sees you, exit the terminal and you're home free. If an airline agent sees you, then just say you've lost your wife/husband/whatever and are looking for them - if boarding is still busy, they'll forget about you in a few moments and then you're free.

The worst case is the airline agent remembers your departing visa status and gets busy with what you're doing - tell them you can't find your spouse and need to deplane to go look for them - and if you can't shake them, ask them to 'deboard' you and give your papers back as you may need to miss the flight...then you can try the trick again on another day.

Once you've done this successfully, the airline has told DHS that you left the country, and as far as DHS is concerned, you're no longer their problem...but you're still in the US illegally, even if they're not looking for you.