Updated at 5:30 p.m. ET

Dennis Johnson was just trying to defend his dissertation — the last step in getting his doctorate in education — in front of a virtual audience of friends and family.

Instead, he became the face of "Zoombombing," a new form of online harassment, when an unknown intruder interrupted his Zoom video conference by drawing genitalia and writing racial slurs on screen.

Johnson finished his presentation, and quickly launched a petition urging Zoom to do more to protect its users — especially now that so many people are relying on video chat in their daily lives and reports of targeted Zoom attacks are on the rise.

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Johnson hopes his experience will lead to change. "This is not an isolated incident. This is a systemic issue," he said. His question to Zoom: "What are you all going to do from a systemic level to deal with this issue? Let me help you. My moment has already been stolen."

Zoom has made several changes to security and privacy, including requiring passwords for all meetings by default.

He's now Dr. Johnson. He plans to celebrate once the lockdown is lifted by going to Disneyland.

"It'll be like I just won a sports championship," he said.

But he also misses talking with students and sharing his knowledge. "I miss interacting with people in person," he said.

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