Re: This has been a policy since at least 2008
Sure, voluntarily - no one's going to force you to do it, you can just decline and jump back on the next flight home.
Besides Sir, if you've got nothing to hide then why on earth wouldn't you want to support us in our fight against terrorism? Heck, no, there must be some goddam reason you're acting so un-American and unpatriotic (apart from not being American). Sir, are you obstructing me in my duties? etc etc etc