Surveillance footage of section 47, level 2, Deep Space 9 in 2371
A Dominion surveillance device in 2373
A surveillance device, or surveillance camera, was a piece of technology used to visually record events happening in a specific area. An eavesdropping device was used to record conversations.
In the late-24th century, Chief of security Odo had several monitors in his security office aboard Deep Space 9 which recorded multiple images of the interior and exterior of the station, forming a security grid. In 2369, Ilon Tandro led a team to the station in order to kidnap Lieutenant Jadzia Dax for extradition to Klaestron IV. With prior preparation, they were able to avoid the surveillance cameras, kidnap Dax and make it back to their ship. (DS9: "Dax")
In 2370, Commander Benjamin Sisko had all of the surveillance cameras on Deep Space 9 sabotaged in order to assist the senior staff in retaking the station from General Krim's forces during the Bajoran coup d'état. (DS9: "The Siege")
That same year, the security cameras in the science laboratory on Deep Space 9 shorted out for 43 seconds when Odo was metamorphosing out-of-control due to contamination with a gas that was toxic to him. (DS9: "The Alternate")
In 2371, after being surgically altered to resemble a Cardassian, Major Kira Nerys searched the house of Tekeny Ghemor for surveillance devices. He later stated they were present but only turned on at his request. (DS9: "Second Skin")
Later that year, Constable Odo placed a surveillance device in the corridor of section 47, level 2 on Deep Space 9 in an effort to discover who was planning on placing a weapon in one of the bulkheads there. (DS9: "Visionary")
In 2373, while investigating a crashed Jem'Hadar fighter on the planet Torga IV in the Gamma Quadrant, a team led by Captain Benjamin Sisko came under attack by a Jem'Hadar unit led by the Vorta Kilana. In order to ascertain the status of a Founder hidden within the vessel, Kilana ordered one of her soldiers to plant a device within the ship. On discovering this, Lieutenant commander Jadzia Dax identified it as a suveillance device. (DS9: "The Ship")