A blanket ban is rarely effective, but apparently it’s especially non-effective in the workplace regarding personal communications:

Checking your personal emails in the office and even researching your next holiday on company time can actually make employees happier and more productive at work, according to a new study.

R. Kelly Garrett, a professor of communications at Ohio State University in the US, has found that everyone - from senior managers right down to entry-level staff - regularly indulge in so-called “cyberslacking” during office hours, and believes that attempts to clamp-down on what is perceived as time-wasting are unnecessary.

“It’s appropriate to just avoid the knee-jerk response that all personal internet use is detrimental,” Prof Garrett told the Associated Press.