Probabilistic identifiers do not rely on deterministic identifiers that uniquely identify an individual. Rather, probabilistic identifiers are simply an approximation of a unique user versus a clear delineation of one. Meaning, there is a chance that two probabilistically identified users may collide and be confused for each other because their probabilistic identifier mistakenly conflates them as the same user. Naturally, the chance for collision is highly dependent on the strength of the probabilistic identification mechanism.
