Not seen for single frame

"A few days ago, in the interest of national
security, you were placed under surveillance as a
person of interest. Shortly afterwards, the equipment
began to malfunction. We'd be very interested in
knowing how you knew that equipment was there and
how you managed to disable it without showing as
much as a single frame on tape."

[...]

"So how did you do it?" he asked. "There were
cameras on the front door, and none of them showed a
thing. Just a flicker and that was it."
"I have no idea what you are talking about," Lois
said, wondering exactly how Clark had managed it.

Pg. 36