<hypocrit>
Copying copyrighted material = freeloading.
</hypocrit>

Copying copyrighted material = freeloading.
Sure?
There wouldn't be many users not being freeloaders, would there?
Doesn't make too much sense to me..

And why do you say "Please" ?

Worst idea yet. The only thing that would do is cause everybody to put up a huge number of large/bogus files to get around the freeloading limits.

There will always be freeloaders, because some people are just a$$holes.

Exactly.. 99% of users would be illegally copying copyrighted material => all these people complaining of 'freeloaders' are freeloaders themselves... HYPOCRITES would be the correct word.

I know its not a great idea only because all someone has to do is dump their internet cache in the folder, but I'm talking about is not just number of files but also the amount or size of them, because you have people just dumping garbage on the network.
And yes, even if you are a modem user, you should share! Limewire and I imagine some of the other gnutella clients have the ability to trim the upload bandwidth being used. And even if you don't share files, the client takes alot of bandwidth anyway!
So if you are a modem user, you shouldn't freeload but even more to the point don't share crap. Share things that are worth something and simply tweak the settings of the program to your connection(don't accept as many out/in going connections and trim the upload bandwidth off you).