For the first time since the Advertising Council was founded in 1942, the organization — which directs and coordinates public service campaigns on behalf of Madison Avenue and the media industry — is introducing ads meant to tackle a social issue of concern to gays and lesbians. The campaign, which is scheduled to be announced by the council in Washington on Wednesday, will seek to discourage bullying and harassment of teenagers who are gay, lesbian, bisexual or transgender. The campaign, created pro bono by the New York office of Arnold Worldwide, urges an end to using derogatory language, particularly labeling...