SAN FRANCISCO — When Renee Jackson began exploring the intersections between social media and the workplace, the young employment lawyer found there wasn’t much being said about the budding legal space.

So Jackson, then an associate at Nixon Peabody, decided to do it herself, writing articles and taking on speaking engagements. Three years ago, she launched the firm’s “Social Media in the Workplace” practice, which she ran until earlier this year. Jackson joined Zynga Inc. in May as employment counsel, but a company spokeswoman declined an interview request.