Late-night traffic on one of the Russian capital's busiest roads slowed Thursday as a couple's explicit escapades appeared across the 9-by-6-meter (yard) display.
The screen's owner - the 3 Stars advertising agency - has told The Associated Press that a hacker attack is likely to blame. City police say they have yet to receive any complaints and have not opened an investigation.
Russian news agency RIA Novosti quoted a city official as saying that Moscow will bolster security of data transmission to ad screens.
Mobile phone camera footage has been posted on popular video-sharing Web sites.
