Muslim Opinion Polls: A Tiny Minority of Extremists?
http://thereligionofpeace.com/pages/articles/opinion-polls.aspx
This is useful to show that pretty much even vile think terrorists do is supported by 10-90% of Muslims depending on the actual question, location of the poll, etc.
For a lot of the 'big questions', such as 'are suicide bombings justified' or approval of ISIS/Al-Qaeda the typical percentage might be 20-35%.
With 1.5 BILLION Muslims this means at least 150 MILLION will support pretty much anything (10%), and some 250-500 MILLION support most of the evil stuff.
Actually it means these numbers will ADMIT to supporting pretty much anything.
Since "Taqiya" (lying for good of the faith) is a recognized, named, and Qur'an proclaimed PRINCIPLE of Islam, it could easily be much worse.
Please add other good links that offer such polls and studies.