The Maelstrom are a gang in Cyberpunk 2077, with their main terrority occupying the industrial sections of the Watson district.
A gang that controls the districts of Watson and the Northside Industrial District (NID). You can easily recognize them by their intimidating faceplates and hostile optic implants, which not only indicates their gang affiliation but also their fetishization of cyberware and cybermodification.
Looking at Maelstrom, you might think, "Now those are some hella bold pioneers of transhumanism." If they were only testing the limits of the human body on themselves, then you'd be right... Sadly, they also like to conduct "experiments" on those unfortunate enough to cross their path. Maelstrom is known for their exceptionally brutal and public gang executions - combine that with illegal braindance production and a manic fighting style and you've got yourself a gang with a reputation as a band of lunatics on the verge of cyberpsychosis. The truth is there's nothing crazy about how Maelstrom operates - at the end of the day it's all about biz. And the more rumors there are about them, the better.