The internet has the reputation of being a place where people can hide in anonymity, and present as being very different people than who they actually are. Is this a problem on Mechanical Turk? Is the self-reported information provided by Mechanical Turk workers reliable? These are important questions which have been addressed with several different methods. Researchers have examined a) consistency of responding to the same questions over time and across studies b) the validity of responses, or the degree to which the items capture responses that represent the truth from participants. It turns out that there are certain situations in which MTurk workers are likely to lie, but they are who they say they are in almost all cases.
We recently launched a ground-breaking feature that helps protect Mechanical Turk worker identities. It has been reported in the literature that Mechanical Turk Worker IDs can be used to identify the worker. This is because Amazon uses the same value for both the Worker ID on Mechanical Turk and elsewhere on Amazon properties like Amazon.com product reviews.