I was googling for my own answer from couple of years ago and was surprised to first find it from an Indian site called "Query Starter" https://www.questarter.com/
This site seems to mirror all questions from several SE sites, but not in realtime. I wouldn't mind if it was stated clearly that they are providing e.g. an accessibility interface or a proxy for slow local connections for enabling access to these sites via Stack Exchange API. Sharing the information is even encouraged:
But it's not. It's just all our content with added
Copyright © QueStarter 2019.
Is SE aware of it already? How SE handles copyright infringement in general?