By good fortune or great coincidence, I met someone in the Inuit art world who was actively involved in German street art in the late 1980s and early 1990s – working with others in stencils, stickers, and posters. He contributed to the publication of “hoch die kampf dem: 20 Jahre Plakata autonomer Bewegungen” (“20 years of autonomous movements posters”) and “vorwärts bis zum nieder mit: 30 Jahre Plakate unkontrollierter Bewegungen,” which on Amazon translates awkwardly to “forward to the down with: 30 years of posters of uncontrolled movements.” When I put “with others” above, he told me that individuals rarely worked alone. Rather, people worked in collectives—by consensus in small associations for a particular protest, or in more long-term antifa movements and support network for autonomous centers (his words, not mine). The first publication is available as a PDF PlakatbuchBand1, and it appears to be reviewed online here. Both publications come with CDs, which may be a little more difficult to track down.
Even though I don’t speak German, I can see in the first publication that some of the themes and graphics found in contemporary stickers date back several years to the mid- to late-1980s, such as “Atomkraft: nein Danke!” (“Atomic energy? No thanks!”) and “Kein mensch ist illegal” (No one is illegal”).
The other weird coincidence is that this guy from Germany goes by kleiner kosmonaut, and when I looked online, I found this:
Can’t make this stuff up!