It may be different in the more rural regions of Russia, but I'm from Saint-Petersburg, and I've never seen anything similar to a police officer go "in 7-11's, local shops, etc, just walk in, take what the want, and leave". They're usually civil, and sometimes helpful (you can ask directions, etc).

There is corruption here, but it seems to be more prevalent among the civil cervants and the higher ranking police officials.

I've always found vast similarities between the USA and Russia but it seems to bring on deep offence if you mention it to an average American.