Well, if memory serves, for the most part haven't most terrorist attacks been coordinated over either completely open channels or over non-technical channels? If I remember correctly, the Bin Laden operations were orchestrated via sneakernet, the more recent attacks in France were orchestrated with check-out aisle cell phones.
The technical difficulties law enforcement faces with terrorism and crime isn't that criminals are upping the ante with complex and difficult to penetrate technology; it's that they're methods are a needle in a haystack, ubiquitous devices and protocols that apparently law enforcement is just having difficulty filtering. Remembering back to a lecture I attended from an officer explaining the technological issues used in modern harassment and abuse cases, often times stalking would be achieved by purchasing a check-out aisle cellphone with a cheap plan, registering it with family tracking from the provider, then putting the phone into Do Not Disturb and hiding it in the victim's car or day bag, using the tracking to get an idea of where the victim went.
Sneakernets and system abuses like this are clever enough certainly, but they're not high-tech solutions for criminal activities. Most of the time just looking at a person's facebook account is enough to get the information you need to do something malicious to them or their property, and terrorists seem well aware of the ease by which they can operate in plaintext or on just normal phone calls. I don't recall any stories about terrorists using an IRC channel, for example, they're just using what they'd normally use.
Most of the surveillance security actions strike me as purely theatre - there's a difficult problem and a convenient scape goat, so rather than do the hard work, law enforcement and governments rely on a scapegoat. Unscrupulous tech vendors abuse law enforcement/government's lack of knowledge and pressure from the public to sell security snake-oil, promising them the answer to keep the people safe.
There probably is a good future where technology does help stop terrorists and criminals, but right now, they're not doing anything special or unique, just different than we're expecting, and apparently that's more than enough.