I just finished a one-month temp assignment doing clerical
work for a bank, in their mortgage department.  First, let
me say that Wells Fargo was one of the most pleasant
work places I've ever been in.  The pay was, unfortunately,
commensurate with my duties.   ;-)

BUT, in order to get this assignment, I signed the most
preposterous agreement you could imagine:  not only get
they have the rights to any software or inventions I might
create during my hitch with them that might have any
bearing on their business; but any PAST creations!

Now, since I don't OWN anything I have ever created in
the past, have not CREATED anything that could be related
to their business; and would not produce any identifiable
or commercially profitable creations during my time with
them, I went ahead and signed the thing.  And in fact I
did not create anything during that period that could
come under the terms of that agreement.

If I ever signed up with them as a direct employee,
which I'd consider doing, I would definitely have to
negotiate my right to produce software for pay on the
side.

Now, I can see one very sound reason for their making
people sign stuff like this:  suppose I were to
incorporate some "invention" of mine, old or new, into
something that I did for them?  Once they were
committed to using it, I could come back to them and
bill them for royalties for using "my" idea.  This is
the kind of distorted behavior businesses are driven
to, under the threat of IP litigation.

Vic