apparently for this reason:
‘Russian lawmaker Valery Draganov on Thursday said the hostility stemmed from ingrained nationalism among the Russian fans, who are loathe to see Zhirkov, an ethnic Slav, represent a team from the North Caucasus, a predominantly Muslim region along Russia’s southern fringe.’
its a shame cause he obviously went back to Russia, cause he missed his home etc, family whatever. and gets booed by his own fans. was always a fan of his but yeh did sh1t all at chelsea