Constitutionality aside, while this does make some sense for the FBI and CIA - because they have people skilled enough to analyze the data and "legitimate" uses in counter-terrorism - it makes no sense to give all that data to agencies like Homeland Security and the DEA, and I also have little confidence that their agents are good enough to even make sense of basic raw data. Just imagine some TSA agent finding a knife you left in your bag and then getting passed to some moron who detains you for hours because he saw that you liked some communist memes on FB and your friend sent you a 9/11 joke.