Twitter today is beginning its test of a radical and controversial change to its service with the launch of a new “Hide Replies” feature. Effectively, this option gives users the ability to wrestle back control over a conversation they’ve started by hiding any replies they feel aren’t worthy contributions — for example, replies that are irrelevant or outright offensive. One of the problems with Twitter — and with many social networks, for that matter — is that an otherwise healthy conversation can easily be disrupted by a single individual or a small number of people who don’t contribute in a positive fashion.