Impostor is useful in scenarios like the following. Imagine you want to
check your (web-based) e-mail from some device you do not particularly trust,
for example some Internet Cafe or a public terminal at an airport. You do not
want to type your password into that machine because it can be intercepted very
easily (using, for example, a keyboard
logger such as this one). Still, you
need to check your email. Impostor allows you to check your email without requiring
you to type in your username and password. In fact, Impostor enables a Single
Sign-On experience.
Now imagine that your inbox contains some confidential information about you,
for example your home address or your credit card number. You do not want that
this information reaches the device you are using - still you want to be able to
read the rest of the message. Impostor's content filtering is adjusted to
fulfill just this requirement: it removes information that you classify as
"sensitive" (and optionally replaces it with "neutral"
information). Still, it lets you view the rest of the web page normally.
So, in conclusion, Impostor was designed to be used from untrusted devices
(for example, devices are not under your control). It protects sensitive
information (such as passwords and other personal information) from being
disclosed to the (untrusted) device - at the same time it can offer a better
browsing experience as it can automatically log you into websites.
