Whenever there is a major sporting event, fans descend on the venue whether they have tickets or not. Some go there with the intention to try and buy a ticket, some go there to soak up the atmosphere with other like minded fans. THIS IS NOT NEWS... Organizers know that fans come en masse and have areas set up for those that don't have tickets, to watch the event because of this. Usually it is away from the stadium so as to not interrupt fans with tickets gaining access.
The main issue that caused the problems is that the staff and security at the Stade De France did not have folks looking out for ticket touts selling fake tickets or screen fans for fake tickets on the way to the stadium. It was very poorly managed and as usual authorities try to pin the blame on the fans YET AGAIN!
What I would like to know is how did the Real Madrid fans all manage to get in without a hitch? Criminals don't usually have a heart for one set of fans in avoiding selling fake tickets to them, unless they were specifically targeted!