Yaroslav Nikitenko, a 29-year-old physicist and environmental activist, woke up on April 12 to a frightening sight.

Graffiti daubed next to the door of his Moscow apartment read, 'Shut the hell up or ..." and alongside it was a drawing of a gravestone bearing Nikitenko's name. He got the message.

The threat was an attempt to end a high-profile campaign against construction of a luxury residential complex that will encroach on Moskvoretsky Park and an ancient pine forest in Moscow's northwest.