Snapchat parent Snap Inc. SNAP, +0.95% is talking to federal regulators about the ways Facebook Inc. FB, -0.11% tried to thwart competition from the rival social media company, including discouraging popular account holders from referencing Snap, according to a report in The Wall Street Journal. Snap’s legal team had been keeping a dossier named “Project Voldemort” about Facebook’s anti-competitive tactics, the WSJ report said, citing people familiar with the project. Snap’s talks with the Federal Trade Commission are part of a larger probe into Facebook’s business tactics, in which the FTC has made contact with dozens of tech executives and app developers. The report cited Gene Kimmelman, a senior advisor at consumer group Public Knowledge, who said the FTC is putting together a picture of what might be a pattern of behavior to prevent competition to the core Facebook business. Facebook’s stock slipped 0.1% in premarket trading while Snap shares fell 0.7%. Over the past three months, shares of Facebook slipped 0.6%, Snap rallied 17.0% and the S&P 500 SPX, -0.49% has gained 1.4%.