It's rather hard to find information about foul language in Russia, because of taboo on the use of obscene language in print. This taboo exists not only among writers, but among scientists (such as philologists) too. It is a big loss for Russian linguistics, because foul language contains a lot of information about history and culture of Russian. At the same time, foreigners have long been attracted to the Russian foul language by its strong expression, imagery and ambiguity.
In most of Russian literature you will not find any characters who swear, though foul language is very common in colloquial speech. Nevertheless, there are some authors who use foul language in their works, but they are mostly from underground, for example S. Dovlatov or V.Pelevin. It makes their narrative fairer and more natural, comparing to many other earlier texts of writers that had been censored. Obscene vocabulary either was used by ports, good example is I. Brodsky. Most of the authors that use this vocabulary in their works, do it not for the shoking but for the most expressive accuracy and for representation of real live speech.
The national identity of the Russian foul language is not in the wide set of vocabulary, but in its frequency distribution. The number of derivatives from foul stems in Russian is truly innumerable, because they are constantly generated by speech.