Thumb was a German Rapcore band formed in November 1993 in Gütersloh. According to the band's official website they appear to have ceased in 2005 into various side projects; Steffen has joined H-Blockx, Jens is in Taetowier Studio, Jan-Hendrik is in Hudson, Claus is in Alternative Allstars and Axel is in Waterdown.
These are photos from concerts where Thumb played, so they may be of other bands that played the concert as well.
Millencolin / Ignite / Schweisser / Thumb / Mink Stole May 15, 1995 Bochum, North Rhine-Westphalia, Germany Uploaded by Please No Garbage