By Olivia Solon and Cyrus Farivar

REDWOOD CITY, Calif. — Ted Kramer seemed on edge. While sitting at a Starbucks store recently talking to a reporter, he kept looking over his shoulder mid-conversation, scanning people and cars passing by.

For years, Kramer, 35, founder of the now-defunct startup app developer Six4Three, has been involved in a high-stakes legal battle with Facebook. He suspects the technology company has hired people to surveil him, because he says he has seen people taking photos outside his San Francisco apartment.

Facebook says the surveillance claim is “absolute fantasy” and denied monitoring Kramer.

Kramer’s concern is far from the most bizarre thing about his lawsuit, which has prompted an investigation by the British Parliament and shows no sign of resolution.

The David vs. Goliath contest pits Kramer’s small startup, which in 2013 built a short-lived app to identify Facebook photos of users’ friends in bikinis, against one of the most powerful technology companies in the world. Six4Three sued Facebook in 2015 in state court in San Mateo County after Facebook restricted its access to the user data that its app, called Pikinis, and thousands of other apps, relied on to function.