Comment by dunham

Cloudflare handles SSL for a lot of sites. It decrypts everything and passes it along.

For certain other sites, with malformed html, there is a bug that caused it to grab random data (headers and body) from memory and include it in the body of the response HTML. (Some html rewriting product that cloudflare offered was broken and it ran on the same servers.)

This stuff got sent to peoples browsers and also to web indexers like Google or Bing.

Google lets you search for stuff and will also show you the original page that it scraped, making it easy to find this data.

Edit: Also you may be seeing more headers in examples because headers are easier to search for.