Data are made anonymous by Destroying all identifiers connected to the data. Requiring all members of the research team to sign
confidentiality agreements. Reporting data in aggregate form in publications resulting from the research. Keeping the key linking names to responses in a secure location
Identifiers are your virtual location when navigating, if you destroy your 'Virtual ID', nobody could identify you. Also, you could hide your identifiers, in this case, there's a small risk.
