Users of Amazon Mechanical Turk generally believe that the workers are anonymous, identified only by a long obscure identifier like A3IZSXSSGW80FN. (That’s mine.) A worker’s name or contact information can’t be discovered unless the worker chooses to provide it.
But it isn’t true. Many MTurk workers are rather easy to identify.
Take a typical worker ID. If you’ve ever used MTurk yourself, you can find your own worker ID on your Dashboard, on the far right:
Just search the web for your worker ID, and you may find a surprising number of results:
- wish lists
- book reviews
- tagged Amazon products
In fact, many workers even have a public Amazon profile page containing their real name and sometimes even a photo, at http://www.amazon.com/gp/pdp/profile/workerID. Here’s my profile:
In preliminary testing with published datasets containing turker IDs, about 50% of worker IDs we tried had a public profile page, and about 30% of IDs had a discoverable real name. A smaller percentage had a photo as well.
The fundamental problem here is that all of Amazon uses the same identifier for the worker’s account. Every interaction with Amazon is tagged by that identifier, and many of those interactions produce public pages containing the identifier, which are indexed by search engines.
We discovered this fact at a CrowdCamp workshop last weekend at the CSCW 2013 conference, and it came as a stunning surprise to a room full of researchers with years of experience using Mechanical Turk.
The implications are sweeping:
* For academic researchers: worker IDs may have to be treated as personally identifiable information. For example, publishing worker IDs online in public data sets may be a violation of worker privacy, and counter to the requirements of the researcher’s institutional review board.
* For workers: if you want to protect your online identity and retain anonymity on MTurk, you should register a different Amazon account expressly for MTurk, and not use the same account that you use for Amazon purchasing. But note that if you already have an MTurk account, creating a new one would lose any reputation you’ve built up.
* For Amazon itself: this is a privacy hole that needs addressing. The best solution would be to use distinct identifiers for MTurk and other Amazon properties (even if the same login account). At a minimum, however, workers and requesters should be made aware of this privacy risk, and workers whose accounts are publicly-identifiable should be permitted to create new ones without loss of reputation.
For more detail, see our working paper, Mechanical Turk Is Not Anonymous, which will be posted by March 7.
Saeideh Bakshi, Georgia Tech
Michael Bernstein, Stanford University
Jeff Bigham, University of Rochester
Jessica Hullman, University of Michigan
Juho Kim, MIT CSAIL
Walter Lasecki, University of Rochester
Matt Lease, University of Texas Austin
Rob Miller, MIT CSAIL
Tanushree Mitra, Georgia Tech