That's BS, pardon my french. Whip out your IPython notebook and do some calculations. In Germany for example, if you are very generous about muslim birth rates

That's BS, pardon my french. Whip out your IPython notebook and do some calculations. In Germany for example, if you are very generous about muslim birth rates and immigration, we can't expect the muslim minority to reach 50% in the next 200 years. If you assume sinking birth rates among Muslims, as was the case for the past decades in Germany and most Muslim countries, especially turkey, the time span is too long to be still talking about Germans vs Muslims. Same with the UK. What islamophobics also conveniently ignore is the unequal distribution and segregation due to subtle and not so subtle discrimination, similar to the Schelling effect. Basically, if London has more than 50% "immigrant" population (most of which aren't muslim), that's not any indication for the rest of the UK.