Grinder(s) are people who apply the hacker ethic to improve their own [biological] bodies with do-it-yourself cybernetic devices and self-mutations. Many grinders identify with the biopunk movement (rarely with cyberculture/cyberpunk movement as well), open source transhumanism, and technoprogressivism.
A biohacker is a biopunk hobbyist who experiments with DNA and other aspects of genetics. A biohacker (or "wetware hacker") is similar to a computer hacker who creates and modifies software or computer hardware as a hobby, but should not be confused with a bioterrorist, whose sole intent is the deliberate release of viruses, bacteria, or other germs used to cause illness or death in people, animals, or plants (in the same way a computer hacker should not be confused with the more popular, yet erroneous, use of the term, describing someone who spreads computer viruses or breaks into computers systems for malicious purposes).
Pat Mooney, executive director of ETC Group, is a critic of biohacking who argues that—using a laptop computer, published gene sequence information, and mail-order synthetic DNA—just about anyone has the potential to construct genes or entire genomes from scratch (including those of the lethal pathogens) in the near-future. He warns that the danger of this development is not just bio-terror, but "bio-error".