Snapchat is rolling out a new feature over the next few weeks that will allow people to unsend messages. The tool, called Clear Chats, lets users retract messages. Users wishing to delete a note will need to do so directly from the thread by pressing and holding the message they want to get rid of. The operation is not perfect. Snapchat says it will do what it can to retract messages, but it may not be able to if the recipient isn't connected to the internet or doesn't have the most recent version of the app installed. The recipient will be notified that they received a message and that it was retracted. The tool still doesn't protect against screen shots. Snapchat says it should reach all users globally soon.