By Audrina Bigos

(CBS) – Four hundred thousand people are expected in Grant Park next weekend for this year’s Lollapalooza music fest.

But with all the people and music come scams and security concerns, CBS 2’s Audrina Bigos reports.

Over four days there will be 170 bands scheduled on eight stages. Headliners include Chicago’s own Chance the Rapper.

Tickets are sold out for the entire weekend. But now there’s a verified ticket exchange, for one-day resale tickets, going for about $130, to VIP four-day tickets for up to $3,000.

“Buy from a licensed ticket broker,” advises Steve Bernas of the Better Business Bureau.

If you buy off Craigslist or from someone off the street, it’s likely a fake they’re selling, he says.

The BBB has already reported several scammers selling counterfeits on fake websites.

Security is expected to be tight.