Google ignores most of the special characters, but searches for some of them. The order in which you write the words matters. As the evidence above shows, URL capitalization definitely matters in SEO. It's just not in the way you think.
Also, keep in mind that, grammatically, names must be capitalized. However, people ignore this rule when they search in the following example. So it's even more likely that they don't use capitalization when searching for terms that aren't normally capitalized. I agree that capitalization doesn't matter in SEO, and that it can only negatively influence you if you create mixed URLs, since they're harder to link to.
In the previous post, Google's keyword tool combined non-capitalized keywords and capitalized keywords, but the search showed different competing pages resulting; therefore, Google considered them to be different keywords. This is because some search engines are case-sensitive, meaning that a search for “Entertainment” will produce different results than a search for “entertainment”. It shows which search engines are case-sensitive, along with statistics showing that 80% or more people search in lowercase letters. Lowercase search dominated all of these examples, ranging from 85 percent to 90 percent of the total number of terms used.
The problem with this is that these repetitions can trigger a search engine's spam detector, especially when it comes to phrases. As you can see in the search results, people usually type the first letter of each word in capital letters, or camelcase, to make it easy to read, but that's not the case when it comes to the URL. The following example is taken from a real website, which ranked exactly the same when searching for a company name, regardless of the case used. It seems that search engines in the UK that search Google on UK IP may see different results when they search first in lower case and then in upper case.
After realizing this, I did a quick search on Google's keyword tool and noticed that Google considers keyword phrases the same in exact match mode. It still takes place, and it can be up to a separate page in a site's ranking for a keyword and the uppercase and lowercase results were 1,450,000 and uppercase were 2,430,000, which is a bit disappointing, since for many keywords, it's going to be a matter of a user's preference on how they'll do it uppercase or lowercase letter a search term.