Rumbas - 8:32 pm on Jan 22, 2011 (gmt 0)
In many ways Yandex will reward your efforts in terms of optimization for the big non-Russian engines as well. So doing well on G will probably have the same effect on Yandex.
FWIW, why do you want to block that traffic? Redirecting is one way to go, but be careful, you might look like a cloaker and take all the traffic out with that baby.
Maybe just a water mark on the images?