You absolutely can and many do pass security without a confirmed seat. That's the practice in the article, passing ticket holders along and telling them the se

You absolutely can and many do pass security without a confirmed seat. That's the practice in the article, passing ticket holders along and telling them the seat will be assigned at the gate, well after baggage is checked and security lines have been waited. Selling standby seats at the same/similar overbook ratio as they currently do wouldn't lead to any more of a dystopia then we currently have.