Strange synching between iPhone 4S on iOS 8 and Macbook on Yosemite.

I recently upgraded my Macbook to Yosemite and my iPhone to iOS8. My Macbook and iPhone 4s started synching automatically. All of a sudden my text messages were appearing in my Macbook. Then just today, a search I performed on the Twitter app on my iPhone and it showed up as a search on a Yahoo search engine (which I don't use) on my Macbook (which showed up after my Macbook sort of locked up, it wouldn't wakeup, and I had to do a hard reboot). I just turned off the iMessage on my iPhone (which I did not turn on). But the search issue is very disturbing. Any explanations or suggestions please?