A stenciled artwork has appeared on a wall in the western England city of Cheltenham, depicting three figures in trench coats and trilbys snooping on a telephone booth.
Cheltenham is home to GCHQ, Britain's electronic eavesdropping agency. The secretive organization found itself in the spotlight after some of its covert activities were revealed by former NSA contractor Edward Snowden.
GCHQ said Monday the agency was "as intrigued as the rest of the residents of Cheltenham about the appearance of the mysterious artwork."
The work has not been claimed on Bansky's official website, but has many of the elusive artist's hallmarks, including the stenciled technique and ironic social commentary.