> There is video of the SL bomber who attacked the church. The ringleader of the attacks was an extremist known to SL intelligence.
You said it yourself. For such cases, law enforcement could easily get warrants from judges. Most judges rubber-stamp most warrants anyway. You'll also find that in the vast majority of recent terrorist attacks, the people doing them were not only "known to intelligence agencies", but had previously been arrested, etc.
The issue many here have is with mass surveillance, which by definition means surveillance of innocents. Not only does this produce a very high "noise to signal" ratio (one of the reasons why the NSA is giving up on the phone records surveillance program now), making it more difficult for them to catch the actual bad guys, but it also sets up a system in which those having that power can easily abuse it.
You said it yourself. For such cases, law enforcement could easily get warrants from judges. Most judges rubber-stamp most warrants anyway. You'll also find that in the vast majority of recent terrorist attacks, the people doing them were not only "known to intelligence agencies", but had previously been arrested, etc.
The issue many here have is with mass surveillance, which by definition means surveillance of innocents. Not only does this produce a very high "noise to signal" ratio (one of the reasons why the NSA is giving up on the phone records surveillance program now), making it more difficult for them to catch the actual bad guys, but it also sets up a system in which those having that power can easily abuse it.