TBH, as far I’m concerned, even if you managed to get the keys off them and they were forced to take a taxi, all that would have been achieved is one drunk driving journey wouldn’t have been made.
Because unless you are prepared to follow them around for the rest of their lives, they are just going to carry on drinking and driving. People with that attitude do it because they are convinced that they will get away with it – they won’t get killed and they won’t get caught.
In my experience the people who are caught and banned for a year from driving, simply never (unless they are complete tw4ts) make the same mistake again.
So many times I’ve seen people completely give up drinking and driving as a result of get caught. And yet they had no intention of stopping before they were caught.