We will be forced to react not with diplomatic, but with military-technical methods, the Russian Foreign Ministry said in a statement.
To me, the technical part of this makes me think of computer hacking. Russia definitely has the resources to pull off some pretty nasty cyber-attacks, especially considering that many attacks already originate there. If they could pull off a large data wipe somewhere important, it could cause huge problems for the U.S.
I don't know how realistic that is, but it made me think.
Racehorse,
If you think those are fun, you oughta see the crap China has been pulling lately. Hacking the Pentagon, selling us laptops and hard drives that "phone home".
The Russkies are just pissed because they've been pretty much relegated into insignificance.