Yes, Karens are everywhere. I don't know if they are predominantly an anglo-saxon thing, but every example seen so far has met that demographic quite nicely.
There is a male version though. For those born in the 70's, you may remember the animated smurfs series, with "Brainy", an obnoxious gamma twit, having the tagline "Papa smurf always says". That is your male proto-Karen. The guy who can't stand to see someone "breaking the rules" and just has to do something about it. In extreme cases, they kill.
Take Michael Drejka.
I know perfectly well that MD's defense lawyer made a dog's breakfast of explaining the Tueller rule. Also - if something more could be done to emphasize that violence was initiated by the guy who got shot, it wasn't. That said, what sunk MD was a combination of two things. First - and you can go see Nick Rekeita's in-depth analysis of the police interviews - he wouldn't shut the fuck up and entirely sank his case by overelaborating from the word go, handing the prosecution more than enough ammunition to tag him a murderer.
The most important one was that, even though he didn't start the physical violence, he initiated the altercation. He considered that public parking spot "his" to guard and oversee - even though he'd been explicitly warned off of doing so - and could not abide seeing someone "break the rules" - so he had to tell that person off.
Now the standard Karen usually initiates violence in a "let's you and him fight" manner, see the stereotypical "Let me talk to your manager" or calling the cops, but the latter case definitely has the potential to get lethal.
So - isn't enforcing social norms a good thing?
Yes. But then most sins are virtues, necessities, or normal emotions taken to an obsessive extreme. C.S. Lewis wrote an entire book on twisting virtues into sin.
So, when someone is "doing something wrong", like playing basketball outside and not keeping up with "social distancing"? Let's leave off the fact that, since they're outside, in the sun, any transmittal from incidental contact will almost certainly die off before they get infected - see both reports on the spanish flu as well as from areas with decent reporting that have lots of sun and people spending time out in it - is it skin off your back except, possibly, indirectly? Yet there is video of some woman screaming at a bunch of kids for just that.
On the other hand, say you're hanging out at a public beach you have access to, but the public parking is closed, and some asshole decides to give you shit about being on the beach, but later comes back after discovering there's nowhere to park, moves the barriers, invites friends in, parks illegally, and sets up on the beach sharing loud obnoxious music with everyone hundreds of feet around.
Now - I don't think anyone but a Karen would really care if they had simply parked, set up, and chilled - unless a cop drove by and gave them a ticket - but the initial boorishness, rank hypocrisy, and ruining the setting for anyone else about demands a response.
The Karen response is to go give those people a piece of their mind, ignoring the danger of being outnumbered to herself and those with her. Making a scene and drama are part and parcel of being a Karen.
The effective response is to just call the local DNR guys. No fuss, no muss, just quietly make the phone call.