One of my coworkers was just telling me her nephews, 20 y/o identical twins who only kinda sorta look identical now, are traveling out of country w/ their mother.
Many airlines now just do facial recognition for gate boarding.
One got on the plane. The other was in the bathroom, got on a few minutes later... and the system IDed them as his brother, freaked out as already boarded. Caused a whole kerfuffle, backed up everyone. They had to pull the other kid off to prove the situation.
what a stupid system... when good ol picture ID and a paper gate pass and a human would work fine.