Best approach is dust off and move on, however recently one person keeps slandering causing mayhem, it is annoying since they hide online one minute in this part of the world the next somewhere else. (let alone a work place).

Person in question is either a scammer or totally mad, so being the bigger person, walk away and ignore, life is too short... Same in the work place; people stab you in the back, while smiling a greeting, they are not worth your time and energy, keep going with your journals and keeping fit.