I would like to see all data which is collected made public after a time period. Say 1 quarter. Exceptions could be granted by a body made up of elected representatives.
This would:
1) Go a huge distance toward discouraging collection of spurious data.
2) Allow the small number of collections which are actually used for 'fighting terrorism' or whatever to proceed.
I also believe that it is perfectly reasonable for law abiding citizens to obtain ALL the data contained in their dossier on request. There are relatively few secrets left about the nature and extent of the surveillance methods used so that argument for keeping secret dossiers on lawful citizens is out the window.
This might have some impact on the capabilities and potentials which our internal intelligence services desire, but in my opinion it is a very reasonable trade-off. The potential for abuse in a surveillance state is enormous. It's really not a question about whether this abuse will happen or not...the only question is when. We in the U.S. are already to far down the road. I don't think it is an overstatement to say that the life of the nation in it's current form is at significant question unless we go father than simply halting the trend but also back up significantly.