Check out which companies are making headlines after the bell Thursday:
Facebook - Shares of the social-networking site fell in extended-hours trading after news that the company was being sued over allegations it scanned private messages, according to a complaint filed in federal court in Northern California.
FireEye - The cybersecurity company reported fourth-quarter revenues that tops estimates and said it would buy Mandiant in a $1.05 billion cash-and-stock deal. Its shares rallied in after-hours trade.
