It's hilarious. I've just learned a bit of Cyrillic during holidays, and even I can hardly stop reading it as "OpeZego" and so on. It must be almost unreadable for people from the many countries with a Cyrillic alphabet.
You can't imagine how often it happens when someone is trying to appear "Russian" or just trying to be fancy. As a native speaker, you can't help but keep reading it in Cyrillic, and the result is completely garbled.
Well, it's not unreadable at all, though a bit ambiguous, for me. I think people who's native languages only have Cyrillic letters don't struggle with it as much as some people who's languages have two official alphabets - i.e. my native Serbian, which has Cyrillic and Latin alphabets, that are equally taugh in schools, accepted by the government and un-prejudiced (well, other than extreme right people who force Cyrillic as the only "true" alphabet [sigh]).
However, it's extremely rare to see Cyrillic mixed with Latin letters in a word or sentence and have it intentionally mean both, so my mind doesn't interpret it like that. That's why P is not R to me or C is not S...
