I agree this is a big issue, for the Your Freedom instance of the application I think it could be solved by including a field which references some unique aspect of the legislation in question (i.e. official title/number of the bill/statute).

I think the merge button is a good idea. For this to work properly I think you would have to attach the duplicate ideas and indicate 'others phrased this idea in x way' so that the slightly different slants on a topic weren't lost.

I think this was a tricky one. I saw lots of users getting angry that their idea had been closed as it was similar to others. In their eyes it may have been slightly different, or even if it wasnt, they probably didnt care, they just wanted to have their say.

It would take quite some work to truly identify what were duplicate ideas (some easier than others). I think it would be better to encourage comment on exsisting ideas by other methods already suggested eg default landing page showing highest rated ideas.

I just demonstrated the value of this ability. I did not search before posting a new idea on this same topic. There are now two threads on the same thing for the moderator to track. I would have no problem if my post were merged into this one. There could be a note from the moderator at the bottom of my post saying similar threads merged by moderator.

If the poster were automatically notified by email that this happened and why, it might ease some of the concerns raised by timlennon.