This SCOTUS decision is really, REALLY bad news! Read this from Sotomayer::

[Curtis]

40. Differences

The first is just a stop and talk. When I used to do this, I would ask the person during the conversation for some ID. Then I'd say something like, "you know, just for safety reasons, I gotta ask. You got any weapons on ya? Mind if I do a quick check for just weapons so I can be comfortable?" So many people say, "sure." Do a quick frisk and note things. Hard things ask what they are. Ask to pull them out and check. Again most people say "okay." Soft things that could be baggies, just brush over them and remember. Don't ask because you're searching for weapons. Then talk. Yeah, I just wanted to ask you about the people in that house....Who are they....Names....Pets....Children....How well you know them....What we're you doing there...? Things like that. Eventually, you can get around to the baggie in their pocket, the pills, etc. It really does work. If not, there's always someone else.

The guy in the ski mask hiding in the alley? Depending on the weather, I'd say reasonable suspicion is easily met and I'd stop and take a much more authoritative approach.

If I were still working, this ruling would have changed the way I did my job.