Maybe I missed something, but isn’t your article’s title 100% false?
Only 6% of the top 10,000 sites hit the Facebook CDN, so it’s 16% of their code that is from Facebook (if all of those hit the Facebook CDN to get the SDK, rather than, say, a 2 KB like button image).
So that’s not 16% of the average site. It’s 16% of 6% of sites.
So on average 0.96% of the code across those 10,000 sites is from Facebook. You’ll update your title to say that, right?
On the flip side, if you wanted to be more sensationalist, you should point out that the Facebook SDK has a cache-control max-age of 1200 (20 minutes) — so a user is not likely to be using it from cache, and most likely will be downloading it again and again. That is, for those 6% of sites that use it.