They've generally been quite good at refusing to let advertisers target on sensitive subjects. It's probably a legal minefield in most developed countries, and it'd be a PR nightmare if there were any sort of adverse effects.

"We won’t associate with an individual’s cookie any audiences considered sensitive, such as those based on race, religion, sexual orientation, health, certain financial information, and others."[0]

[0] https://support.google.com/adwords/answer/2497941?hl=en