Could Terrorists Hijack Your Brain? is a good paper by Emily Singer which deals with this potential fact: technological advances in the not-so-distant future may make it a possibility.

Most bioweapons research has focused on traditional biological agents, such as anthrax and smallpox. But that focus is dangerously narrow, the report says; emerging technologies in biotechnology and the life sciences could be hijacked to take control of genes, immune systems, and even brains. (...) the report recommends that technologies with dual-use potential -- those that can be used to either help or harm humanity -- be continually reassessed to take account of rapid advances in biotechnology

Some examples of bioterrorists threats:

Newer technologies such as targeted delivery methods that zero in on the immune or neuroendocrine systems could make it easier to use bioregulators in insidious ways.

Terrorists could also co-opt relatively new technologies, such as synthetic biology, which aims to build organisms that can detect or produce chemicals or perform other functions; and RNA interference, a technique that allows scientists to easily control gene expression.

Why do I blog this? I don't want to play the party pooper here but I was interested in this balance: being careful with technology that may help humanity because they could easily be reversed...