Except that in what way is PRISM preventing you from being able to assemble ?
There is NO evidence that the NSA et al are using this information to target anything other than the most serious of terrorists. Until we evidence of the contrary I fail to see how these lawsuits will be able to stick.
The 1958 Supreme Court ruling struck down a law that required groups to provide their membership lists to the State of Alabama. They don't have to "prevent" people from being able to assemble, but building lists of which groups people belongs to still violates their "right to pursue their private interests privately". So in large part, the right to assemble also includes the right to be part of any group (even communists!) without the government needing to know.
But again what evidence is there that the NSA is creating these list of groups ? They could just be simply looking at which individuals a person is speaking to. It is a subtle distinction but legally a significant one.
I just seem to see a lot of conjecture but no actual evidence.
It might be legally significant, but technically, there is no real difference.
Given your social network, and training data consisting of the public members of a group you can use a semi-supervised learning algorithm to determine group membership. Since social networks have a small diameter and the public members are typically well connected, you would expect this approach to be fairly accurate. Or rather, accurate enough to act on, if you do not need to provide legal justification for your decision.
What's the required legal justification for putting someone on a no-fly list?
If you want to give some real world basis to the legal distinction you need oversight and transparency. In particular, global analysis of the whole dataset must be illegal, since it pretty much corresponds to total surveillance. Your results might not be completely accurate, but they don't need to be if you can act once you have something like 51% confidence.
There are a number of possible interpretations as to what thety are doing and some interpretation of what we have seen and read regarding the NSA data collection probably exists that would probably make most of us pretty happy.
The problems are:
(a) we dont know what they are actually doing and
(b) we cannot trust them not to lie to us about what they are doing, one way or another.
The other problem is that the NSA has made it clear that in its opinion collecting metadata on a call is fine at any time, for anyone/everyone.
Metadata on a cell phone clearly includes time and location of cellphone/receiver checkins.
It is absolutely reasonable to assume that, if they want, the NSA can track the location of any person carrying a cellphone; or - given that they are storing this data - reach into the past and know exactly where you were, and when.
that is a remarkable power, IMO.
Hook that data up to a computer display and holy cow, that is a powerful tool.
Frankly, it would be awesome. if it wasn't for the fact that you, specifically and personally, appear on that display.
One way for them to stick is if "collect it all" surveillance is judged to violate the Fourth Amendment regardless of whom the agencies are currently targeting.
While I disagree with this position from a policy stance, it may have legal weight. Courts are loathe to rule on things based on hypothetical future harm.
There is NO evidence that the NSA et al are using this information to target anything other than the most serious of terrorists. Until we evidence of the contrary I fail to see how these lawsuits will be able to stick.