Hooray. I am apparently Osama Bin Laden.
I wouldn't consider using suicide bombers though. Much more likely to use kamikaze robots.
Seriously. Take the recent trend of ubiquitous availability of throw away "burn phone" smartphones. Those are straight up, fully programmable computers with very sophisticated/powerful innards, often with a real USB port that can be put into hub mode instead of client mode. There's a real linux underneath in most cases, since most are android devices. For about 70-80$, you can turn one into a mostly autonomous robot crawling bomb. There's all manner of high powered explosive compounds one could attach to such a thing (and synthesis is not that hard), and with the cameras and ubiquitous facial recognition software out there these days, having a very specific bomb activation trigger is quite doable. I am thinking little things that can be introduced into a wall vent, or that can crawl around underneath city streets and self-navigate to specific areas of interest autonomously, then wait for further instructions on weather to detonate or not. So much more terroristic than foolishly sacrificing people brazenly. Basically, I would put the USB port into hub mode, attach a serial port cable to it, pop a little arduino onto that serial interface that directly controls the robot limbs, and then use the phone's various sensors (magnetometer, photometer, cameras, accellerometer, GPS reciever, etc.) and communications systems (Bluetooth, WiFi, GPRS/EDGE/3G/4G,UMTS, etc) to make the actual movement/detonation decisions. A few size D batteries, some cheap robot parts, and 3D printed chassis-- One could have little mobile sticks of high explosive going all over the place in places humans just could not reach, taking up positions to take down civil infrastructures, and automatically coordinating with each other with efficiency far exceeding that of any human conspirators. (Cheap cellphones of this class have enough processing power to use pretty damned hardened encryption to communicate with each other with.) The direct loss of human life is not necessary to further political goals. Strategic removal of civil infrastructure is more than adequate to cause/force significant political pressure on political figures. In fact, the more it is non-fatal, and simply denial of service in nature, the more effective it would be. It causes the public to not feel directly threatened, but to lose confidence in the leadership abilities of their authority figures, leading to increased logistical difficulties of the power elite retaining power. A few very small, underground explosions intended to simply knock out television and radio broadcasts, take down traffic lights (rather than reprogram them), cause toilets to overflow over a major metropolitan area, take out internet or cellular phone service by taking out fiber optic interconnects at crucial interlink nodes, etc-- can have a much bigger political influence than being yet another suicide bomb ring leader. Boston Marathon bombing? Do people talk about the political motivation, or the bombing itself? It's much easier to guide the public's reactions by selectively causing peevedness than it is to control them with radicalized fear.
Thankfully I am NOT a terrorist, nor a villian, so the above would never happen-- but the technology and wild-type knowledge and skillset are highly prevalent in the modern maker community. People seem fixated on making little quadcopters, but really, small robots designed to navigate utility conduits or sewers would be both easier to make, and much more effective at causing the above kinds of disruption and chaos-- not to mention being harder to stop and detect. Really, that pandora's box is already wide open. Rather than focusing on drumming up paranoia, the current power elite should instead focus on applying political calmatives to the public, so that the individuals with those talents and access to those materials simply have no inclination to create such things to begin with-- that's the best strategem for dealing with such forms of REAL cyber-terrorism, but that does not rake in the votes like a good old fashioned boogeyman does.
At the most, I would enable such boogeymen via postings like this one, which would turn them on to the various options in front of them that they simply did not consider. Really, there are so many ways to create miniaturized versions of WMDs that it simply isn't even funny. Instead of bombs, the same tiny crawler robots could infiltrate subway ventilation systems and contain mini wet-chem suites that produce deadly gasses-- Crawling gas grenades-- for example. Or just be ideal little mobile habitats for horrible human pests, like bedbugs or cockroaches, and use them to infest buildings in a controlled and programmed fashion. Perhaps spreading legionella around, or some similarly dangerous biopathogen. So many ways to use that tech for terrorist actions. Simply no need to sacrifice human lives for such activities. Cheap robots are up to the task already, and are sufficiently COtS hardware and software derived to enable mass construction in a garage with simple consumer grade tools.
So, budding villians out there-- Be more original and savvy with what's on the table, and avoid using human mules to do your dirty work. Human minds are much better applied producing creative and novel solutions to problems than they are being zealot detonation systems. Also, be more original and creative in your applied methodologies to shift political control away from the political elites you are having a beef with than simply killing as many people as is possible. Killing people's lawns instead of the people themselves, is a better methodology, when carefully and intelligently applied. Use your international network of followers{minions} to increase your production rate of actual cyber-terror devices, rather than training them to BE terror devices. A 100$ robot is more reliable, cheaper, and less likely to arouse suspicion until it is too late than any human with dynamite strapped to them ever will be. Be more intelligent, wont you? At the very least, use social engineering to get innocent people to do your dirty work in purpetuating your denial of service type actions, making enforcement operations more difficult, or some similarly crafty and nefarious approach. Jumping straight to suicide bombers shows a decided lack of intellect, cunning, and creativity on your part. I sure as hell wouldn't follow such an unoriginal leader, that's for sure.
.. You know, reading my own spoiler text above, I would probably make a pretty good villian if I really wanted to... That's kinda scary.