There have been a number of reports since the middle of April about Google Chrome using up lots of bandwidth. It would appear that in the background it's precaching web sites. In some cases are using 30GB a month in bandwidth.
1) Type: chrome://flags/ into the address bar and disable the option:
Prerender from omnibox Mac, Windows, Linux, Chrome OS. Enables prerendering of suggestions from the Omnibox and predicts appropriate network actions (prerendering, Instant, DNS preconnect) by calculating a confidence value for each Omnibox result.
2) Go to Chrome settings and click on "Under the Bonnet" and disable "Predict network actions to improve page load performance".




