No, of course not.
I think FR got noticed partially because of bandwidth myself - everytime I saw somebody direct-linking a pic into their posts from TO's website, I felt like e-mailing them and saying "hey, you ought to at least host it on your own webspace, they have to pay for that you know". I chose not to because it's not my place to play net nanny.
FR probably got noticed as well because quite a few of The Onion's articles and graphics that were posted here did not cite The Onion.
Googling through some of those other sites, I see many cited The Onion. They may not get letters because they did, but nobody here knows who got letters besides FR.
From Faq at The Onion on linking, etc.
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