[jack6e]

Probably not many. The most recent SO developer survey said only 20% of respondents thought responsibility for unethical code fell on developers, compared to 80% thinking designers/managers should be responsible.

That's globally. I imagine the sense of responsibility decreases in ethically-gray areas like nation-state warfare against adversaries, and among developers working in strongly hierarchical, military(-esque) environments, for autocratic regimes focused on destroying national/ethnic/religious enemies (as this appears to have been done by).