dig MX stopwatching.us | grep -c google.com
  >>> 6

  curl https://rally.stopwatching.us/ |grep -c 'google.*\.com'
  >>> 6

  curl https://rally.stopwatching.us/ |grep -c facebook.com
  >>> 1

  curl https://rally.stopwatching.us/ |grep -c youtube.com
  >>> 0
  curl https://rally.stopwatching.us/ |grep -c youtube-nocookie.com
  >>> 1
  hey, at least someone /thought/ about it

  curl https://rally.stopwatching.us/ |grep -c typekit.net
  >>> 1

  curl https://rally.stopwatching.us/ |grep -c twitter.com
  >>> 5

  curl https://rally.stopwatching.us/ |grep -c cloudflare.com
  >>> 3

EDIT: I should note that these could be harmless <a...> links, but most aren't, and I'm too lazy to update the regexes and rerun. You get the point though.