Hi Tech,
From one point of view it is a bandwidth thing, yep, it's just a bandwidth thing. Keep things as small as you can, to keep the downloads down. Imagine if every piece of Google code was as big as it "should*" be, and then having to download all these little chunks of code throughout the day. It'd definitely tot up pretty fast..and furthermore it is that the code cannot be too easily analyzed and hacked by a third party.
Users (like e-mule users) do it for reasons so their ISP won't block their P2P traffic that easily, ISP and Google do it for the reasons mentioned above, malcoders do it on a random basis to get under the radar of webmasters and website admins to redirect to silent malcode download sites, and this code should be blocked by the avast shield,
pol