Yes, this is true. Nobody really knows how many of these contain elements that should not be there. I can't think of a concrete way around it that's realistic. But I think user ratings on an official site are a good thing and are normally fairly accurate.
I am not implying this at all. In fact, I am a huge fan of open source software. I simply offer the advice to check what you are using first as there can be issues, as reported.
I'm not the biggest fan of that term myself, but it's just something known in the web world.
I prefer to think of it as internet marketing as far more goes into it than on page HTML optimisation and such. The real agencies will work with a company to help build and develop a brand and continue to work with that company over a long period.
The results are exactly as reported. The ones published are from last week, but today the top 20 results are still dominated by websites doing the same.