\section{Security Considerations}
\label{sec:security}

The security considerations in \citenorm{draft-ietf-impp-cpim-pidf}
apply, as well as \citenorm{draft-ietf-simple-presence}. Compared to
PIDF, this presence document format reveals additional information that
can be highly sensitive. Beyond traditional security measures to protect
confidentiality and integrity, systems should offer a means to
selectively reveal information to particular watchers and to inspect the
information that is being published, particularly if it is generated
automatically from other sources, such as calendars or sensors.

Like any information retrieved by reference, the information provided in
the \xmlelement{card}, \xmlelement{icon} and \xmlelement{info} elements
may refer to data types that expose the watcher to security risks.
