This excerpt taken from the WBD 20-F filed Jun 18, 2009.
Specific uncertainties associated with the tax treatment of ADS holders
The Russian tax rules in relation to ADS holders (that would affect U.S. holders) are characterized by significant uncertainties and limited interpretive guidance. Russian tax authorities have provided limited guidance regarding the treatment of ADS arrangements, and there can be no certainty as to how the Russian tax authorities will ultimately treat those arrangements. In a number of clarifications, the Russian Ministry of Finance stated that ADS holders must be treated as the beneficial owners of income from the underlying shares for purposes of the double tax treaty provisions applicable to taxation of dividend income from the underlying shares. However, double tax treaty relief is available only if the tax treaty residence of the holder is duly confirmed. It is currently unclear whether depositories will be willing or able to provide residency certificates for ADS holders or implement procedures for holders to benefit from applicable tax treaties. Thus, while a U.S. holder may technically be entitled to benefit from the provisions of the United StatesRussia income tax treaty, in practice such relief may be difficult or impossible to obtain.
If the Russian tax authorities were not to treat U.S. holders as the beneficial owners of income from the underlying shares, then the benefits discussed below regarding the United StatesRussia income tax treaty would not be available to U.S. holders. Russian tax law and procedures are also not well developed, and local tax inspectors have considerable autonomy and often interpret tax
rules without regard to the rule of law. Both the substantive provisions of Russian tax law and the interpretation and application of those provisions by the Russian tax authorities may be subject to more rapid and unpredictable change than in jurisdictions with more developed capital markets.