What did the court decide in Faragher v. City of Boca Raton?
Answered for: US
An employer is subject to vicarious liability to a victimized employee for an actionable hostile environment created by a supervisor with immediate (or successively higher) authority over the employee
The Court set out when an employer is vicariously liable for a supervisor's harassment and the affirmative defense available in some cases. The sentence above is the court in its own words.
This answer is true in US and nowhere else on this site. Another jurisdiction is another answer, or an honest gap: see what has been read for US.