Is there a way of turning off the share feature? Its a bit pointless for my site as you have to be registered to view content so if you shared it on faceboook etc. it wouldn't let you see it anyway, but is still a process working in the background, just seems a pointless feature. 

Rather than turn it off per forum etc, if you wanted to stop it completely go to ACP > System > Site Promotion > Sharing

For each item in the list click the green 'enabled' button to turn them off as required.