Freedom of Speech vs. Xenophobia and Racism

It is a very difficult matter to keep the suitable equilibrium between two fundamental human rights: the freedom of speech, and the freedom from racism and discrimination. As you try to limit discourse promoting speech, you quicky find yourself limiting freedom of speech, either on the media or the Internet. Mr. Michael Head, member of the European Commission against Racism and Intolerance (ECRI - "All human beings are born free and equal in dignity and rights"), was the rapporteur in charge of summarizing the Expert Seminar: Combating Racism while Respecting Freedom of Expression, hold in Strasbourg (16-17 November 2006 - get the proceedings in PDF). A paragraph in the proceedings, that has strongly caught my attention, is the following one:

Freedom of expression and freedom from racism and racial discrimination are not conflicting, but complementary rights. We should keep in mind that human rights are interdependent and interconnected. This means that (i) there can be no such thing as two conflicting human rights and that (ii) human rights need to be interpreted in light of each other. (pg. 7)

To what extent is this proposition just an intellectual wording? Having expent more than five years building Internet filters in order to avoid abuse in certain situations (where the Internet access is intended for work or study, like at the workplace, or the schools), this is still a fundamental question. I am certainly convinced of filters being not the solution but an aiding tool for some situations.

But, when does security prevails over freedom, in other words? (note that I do not answer the question)

As a side note, the Council of Europe promoted a treaty named Convention on Cybercrime in 2002. This treaty, regarded as limiting freedom of speech by the Electronic Privacy Information Center, and its complemetary Additional Protocol to the Convention on cybercrime, concerning the criminalisation of acts of a racist and xenophobic nature committed through computer systems, have been regarded in the expert meeting as useful tools for combating racism while protecting freedom of speech. I must note that Spain signed but not ratified the first convention (what means nothing: Spain is not legally required to implement the measures proposed in the convention), and simply ignored the additional protocol.