Dana-Farber Cancer Institute, a Harvard Medical School affiliate, announced Jan. 22 it’s requesting retractions and corrections of scientific papers after a British blogger flagged problems in early January.

The blogger, 32-year-old Sholto David, of Pontypridd, Wales, is a scientist-sleuth who detects cut-and-paste image manipulation in published scientific papers.

He’s not the only hobbyist poking through pixels. Other champions of scientific integrity are keeping researchers and science journals on their toes. They use special software, oversize computer monitors and their eagle eyes to find flipped, duplicated and stretched images.