A while back I answered a quesation about recording dreams (https://dreamsandbass.wordpress.com/2012/09/25/can-i-record-my-dreams/ ) and if it was possible usin MRI. Recently a new study and research has prooved that we might be able to at some stage (http://www.abc.net.au/news/2013-04-05/machine-predicts-images-dreamt-while-sleeping/4610898 ). I am yet to read the paper (and am unlikely to be able to for a few weeks) so I can’t say for sure if the media is reporting this properly. I note it is a long way from fully recording the experiance of a dream and its only about 50-60% accurate. The article pens the idea that it could be used to prevent nighmares but doesn’t tak about how, or in fact if this would be a good thing or not.
Nighmares are, in general ok things to have, they help our brain process fears and anexities, and help us deal with them, without them maddness is likely to ensue I suspect. So I wish the researches the best of luck with recording dreams and preventing problematic nighmares, but caution the potential for abuse of the tool when it is fully developed.