An amount equivalent to $10,000 will serve as the limit which could be carried away without being declared. The new law takes effect from July, 31. Furthermore, it seems it would be worthwhile to store the customs declarations for a while now.
The term “amount equivalent to $10,000” implies the amount could be in dollars as well as in roubles and any other currency. As for plastic cards, the policy remains the same.
The worst trouble might be with those who brought their money here before the new restrictions were introduced and who will now have to go back with the same amount. The warning from the customs is that you should keep your customs documentation as long as possible.