The U.S. Department of Justice is launching a probe into possible antitrust violations from four Big Tech companies, Apple Inc., Amazon.com Inc., Facebook Inc. and Alphabet Inc.’s Google, adding to growing competition law concerns for their in-house counsel.

None of the companies have yet taken the 2009 Intel approach—hiring an experienced DOJ antitrust division lawyer as general counsel—but all four have senior counsel or executives with that background. Those lawyers could play a key role in what happens next, though companies did not respond to requests for comment on what competition law work they’ll be keeping in-house or if they’re growing teams in response to Tuesday’s probe launch.