It actually came up in a game 2 weeks ago.
I was playing a rogue and I was trying to sneak up on an enemy that I knew was a high elf rogue who used Booming Blade a lot, I was going to take his weapon before the fight started so he would essentially be screwed.
Problem was that evidently he had a 19 passive perception somehow...
He spotted me when I got 5 feet away and we rolled initiative, which I won easily so I was just like, "Well, he still has not drawn his weapon so I take it anyway as my action."
The DM just looked at me and said, "Ummmm ok, let's call it there and I will see how that is going to work."