In 2009, cosmonaut Gennady Padalka complained
to a Russian newspaper that he wasn't allowed to use the bathroom on
the American side of the Space Station.
As it turned out, Padalka actually blamed the closed bathroom door
on the Russian government, which had started charging NASA for
resources used by American astronauts in 2003.
The United States reciprocated by asking the Russians to keep out of
its facilities, including the toilet, which NASA paid $250 million
to develop. Padalka told the newspaper that the bathroom shutout was
having a real effect on his cosmonauts' morale.