Crying wolf with an email.
It's nice that someone is looking out for the average Joe, but how about some specific examples of what specific apps are doing, and which are the most dangerous? It is one thing to know where a person is to improve the function of the application, such as Wikihood, but it is another to do it with some malicious intent. Some might say it would be illegal to mislead a person to allow location services because they think it is important for the function of the apps, and another to use the information to gain some other personal information to rob you of something. I compare this article to one that tells people that Guns can kill people, and many people are alloowed to buy them. There is potential here, but not a problem for the majority.
if someone is committing a crime, let it be known. Just because the potential is there, does not mean our favorite apps are dangerous to us.