Chaz has addressed the question of how the security department handled this issue of hidden badges on convention members and of people without convention badges. He's the chair, and taking responsibility is the right thing to do.
Anime conventions take money, and paying members providing that money, to run. Anime Los Angeles is a non-profit operation, and unlike Comic-Con International or AnimeExpo, it doesn't get tens of thousands of dollars of sponsor money (or the attached strings). Nobody is getting rich off of this, and many convention volunteers (myself included) paid for the vast majority of our con expenses, including big things like our hotel room and transportation from home to Los Angeles and small things like award certificate paper and printer ink, out of our own pockets.
As Chaz said, Anime Los Angeles also had space concerns this year. When last year's membership exceeded the number of badges printed, the con's hotel people started phoning other hotels they work with to see if Anime Los Angeles could move to a bigger space. It's not easy, though, getting a hotel that will deal gracefully with an anime convention, much less a 2,000 person anime convention. Try doing that barely a year out without changing to drastically different dates. It wasn't possible, but it was plenty of time to book the Burbank Marriott for January 2008 (although they still had to move three weeks earlier). There was already an agreement with the Airtel, but that meant making sure the convention didn't become so crowded that the fire marshals would shut it down. There's a fire station near the Airtel (because it's right next to the airport) and the fire marshals came through the con. They didn't shut the con down, and that's a good thing.
So, if you were a paying member and you're unhappy with how security was working, you have some right to be upset.
If you were not a paying member, if you "just came to hall cosplay" or "hang out with your friends" you need to think about those statements. If it were not for the paying members, there would be no hotel, no space, no hall cosplay, no friends getting together in a hotel, no convention. "I wasn't messing with anything that belonged to the con" only stands up if there is no con.
If you're ghosting, you're stealing from the people who provided their time and money to help make the con happen, whether they're organizers or paying members.
Friends don't let friends ghost cons.