Granted we don't know how terrorists plots were uncovered and or foiled just as we don't know if there were any plots uncovered by collecting and searching meta-data. I would have some level of difficulty in believing the people who are in charge of collecting and reviewing this data since they seem to have had some "difficulty communicating" with the american public about what and why they were doing it.
Yes we can't put the genie back in the bottle, but just as cars improve I believe that we can hope and work for safer driving. I understand that for the government(and any other entity) to support me I have lost my right to total privacy, but I sure would like to know what the government is doing with my information.
I realize that I am probably a minority but I still read the users rights and responsibilities when I connect to an organization which is going to share my private information and I can and have chosen not to connect with them if I didn't feel comfortable with sharing the data which is me.
I have been a victim of identity theft because someone stole personal information. Since then I have, as much as possible, attempted to find out who and why has accessed my data.