According to the OC Register:
The ticket booths at Disneyland Resort were temporarily shut down this morning but have reopened after authorities determined that a suspicious white powder found on the park’s ticket booths was harmless, authorities said.
Cleaning crews reported early this morning that they had spotted an unusual white substance at the windows of several ticket booths. Police were called in at 7:30 a.m.
Some guests entered Disneyland and California Adventure when the parks opened at 8 a.m., Disney spokeswoman Suzi Brown said. But when the powder was found on more ticket booths, park officials decided to temporarily hold back all guests from the ticketing area until police could investigate the powder. The booths were shuttered at 8:45 a.m.
The parks were never closed, as some guests were allowed into them. The ticket areas were closed down for a while, though, keeping other guests out.
“We thought it would be best to close off all ticket booths until we could make sure there was nothing hazardous,” Brown said.
Anaheim police called in a hazardous-materials unit from the Anaheim Fire Department. Samples were tested and soon determined to be nothing more than a fine, nonhazardous sand, said police Sgt. Rick Martinez.
Guests and employees who were held back for more than an hour were allowed to enter the ticket area and the amusement parks at 9:45 a.m. Martinez said.
“The safetey of our guests and our cast members is our top priority,” Brown said. “The measures that were taken today were done so in an abundance of caution.”
Investigators were working with park officials to review surveillance video, looking for who might have deposited the substance on the ticket booths. No arrests had been made.
“We’re not sure if it was a prank or a deliberate attempt to disrupt park operations,” Martinez said. “Either way, this is serious business. And we will be following up.”