KSU emerged in Ustrzyki Dolne in the late 1970s and became one of the foundational bands in Polish punk rock. The group's name came from the local vehicle registration prefix, tying the band directly to its Bieszczady roots. Built around Eugeniusz "Siczka" Olejarczyk, KSU started by absorbing Western rock and punk broadcasts, then turned that influence into direct, rebellious songs shaped by local frustration, youth culture, and the restrictions of life in communist-era Poland. The band's early years were marked by unstable conditions, censorship, lineup changes, and limited access to recording, but its reputation grew through concerts and circulated recordings. Pod prad, released in 1988, became a key document of Polish punk, with songs that remained staples of the scene. Over time KSU's music widened from raw punk into a broader rock sound while keeping its defiant character. Decades later, the band remains closely associated with Polish punk history, regional identity, and songs that speak from the perspective of outsiders and working people.