Facebook is the largest social network on the planet and wants to stay that way. But among its 1.2 billion users are those “friends” who are doing their darnedest to make the deactivate button a trending topic on Twitter. That’s good news for people who want a simpler life, but bad news for investors. Facebook was concerned enough to conduct an experiment in 2014 on the kinds of things that annoy people. Along with the University of California, San Francisco, and Cornell University, Facebook secretly and randomly gave some people more positive stories in their News Feed and others more negative updates, which obviously led users to also post more positive or negative responses. It also launched the “Facebook Feedback Panel” last year, which was part of the social network’s effort to improve the quality of its News Feed. Approximately one-third of Facebook users take breaks from their accounts by deactivating them, according to interviews of 410 current and former Facebook users carried out by researchers at Cornell University last year. (Deactivation merely hides the account from Facebook friends, and the site retains all the data so it can be reactivated by simply signing in again.) Some people said they left the site to avoid a boss’s friend request, while others felt it was becoming addictive and wanted to spend less timing scrolling through other people’s lives. But here are the 10 most annoying Facebook users as chosen by our panel of experts: http://www.marketwatch.com/story/10-most-annoying-facebook-u...