When you are implementing a new technology, please take some time to actively consider all of the potential consequences you can think of. Maybe your new tech just needs simple safety-considerations similar to power tools (dangerous, if misused). Maybe your new tech will disrupt existing structures that many people rely on; do you have a plan to handle that? Can someone easily use your new tech to undermine civil rights or basic freedoms?
Obviously we can't foresee everything, but we can at least try to consider the potential consequences to the world, society, and people outside of tech. I know it's hard to walk away from a cool idea. It's even harder to do the right thing when it risks your salary - or your safety. For better or worse, this kind of question needs to be part of the new-tech development process. As Dan Geer said[4][5] in a recent keynote, "You have not picked a career. You have picked a crusade."
[1] I strongly encourage everyone to watch this 30c3 talk[2] by Quinn Norton and Eleanor Saitta (or read the transcript[3]).
[2] https://media.ccc.de/v/30C3_-_5491_-_en_-_saal_1_-_201312272...
[3] http://opentranscripts.org/transcript/no-neutral-ground-burn...