I am a computer engineer, and what I can tell you is that "grid" computing
is a very powerful way to process information. It is like having a
multi-million dollar supercomputer for free.
It looks to me like they are using this for molecular/protein research,
which is very, very computationally intensive (i.e., it takes a lot of
work!)
These are very basic, fundemental research problems which have far-reaching
consequences. It is good research.

They probably are taking advantage of our computers for their own needs -
but it might not be such a bad thing. They will only use your computer when
you are not using it (as a screen saver), and yes, they will probably patent
and make money on their discoveries - but even so, knowledge is good, and if
they get a good product on the market soon, or make a scientific
breakthrough, we will all be better off, no?

   Good luck to Nicol?s!

United Devices is a for-profit operation, as anyone can purchase their
products, services, etc based on their needs for computing power.
Your PC won't be involved in those private projects.

Besides that, they run the grid.org project which among other
projects, gives CPU time to University of Oxford and the National
Foundation for Cancer Research.  That one you can be involved in.  

Personally, I don't think anyone would be taking advantage of your
computer through grid.org.  Cancer research doesn't come for free and
it takes time.  Through the grid.org project, the additional
processing helps cut that time.  The best we can hope for is medicines
and cures to arrive sooner?  Since I don't use my spare CPU cycles and
I just leave my PC's on anyway, so I donate them to the cause.

The app can be set to run as a screensaver only, it can be set to run
all the time, or just speciific days/times.  I have some instructions
available from the URL below on how you can install and set it to
specifically do cancer research.  By default, I believe you get
selected per download for what needs to be done, which could be
anthrax research or otherwise.  I'm partial to cancer research myself!
;-)    http://www.gotcancer.org/participate.htm#research

--
Larry...the patient formerly known as Lympho Larry!