  Contact tracing is a very powerful method to implement and enforce social
distancing to avoid spreading of infectious diseases. The traditional approach
of contact tracing is time consuming, manpower intensive, dangerous and prone
to error due to fatigue or lack of skill. Due to this there is an emergence of
mobile based applications for contact tracing. These applications primarily
utilize a combination of GPS based absolute location and Bluetooth based
relative location remitted from user's smartphone to infer various insights.
These applications have eased the task of contact tracing; however, they also
have severe implication on user's privacy, for example, mass surveillance,
personal information leakage and additionally revealing the behavioral patterns
of the user. This impact on user's privacy leads to trust deficit in these
applications, and hence defeats their purpose.
  In this work we discuss the various scenarios which a contact tracing
application should be able to handle. We highlight the privacy handling of some
of the prominent contact tracing applications. Additionally, we describe the
various threat actors who can disrupt its working, or misuse end user's data,
or hamper its mass adoption. Finally, we present privacy guidelines for contact
tracing applications from different stakeholder's perspective. To best of our
knowledge, this is the first generic work which provides privacy guidelines for
contact tracing applications.
