I get a lot of comment spam, some of which appears to be keyed to the content of a post. So if I mention UGGS in a post, it’s often the case that some UGGS knock-off site (or more likely, their affiliate advertiser) will attempt to leave a comment that advertises the knock-off and links to their site. Now, I have software the purpose of which is to allow me to manage the comments, so I believe that I catch most of these (I get an email asking me to approve or delete comments). Nevertheless, I can posit all sorts of scenarios where I miss the offending link (like when the email gets spam-filtered). I can also posit a scenario where I receive a notice letter and can’t act promptly to remove the offending link (like if I want to take an Internet-free vacation, for example).
Also, I link to defendants’ sites often when I am discussing cases.
So there may quite a few links on my entire site that link to infringing merchandise. Granted, a small percent of probably 10,000 outgoing links, and all of them either inadvertent or fair use, but you know how lawyers twist things.
I’m the guy who co-authored the article arguing for Notice and Take-down for trademarks, and I find that SOPA makes me nervous.
BTW, embedded above is the Khan Academy and is a fairly lucid introduction to SOPA.