Police are now trawling social networking sites and tracking text messages to find the organisers of a wild party shut down by the riot squad in Sydney.
About 1500 people crammed into a Camperdown warehouse in Sydney's inner west for the party which was publicised through Facebook and other online forums.
Nearly 1km of Parramatta Rd was closed Sunday as police tried to get partygoers out of the warehouse amid fire and safety concerns.
Revellers pelted police with bottles from upstairs windows.
About 50 local officers were joined by a huge back-up force, including the public order and riot squad, the dog squad, Polair (New South Wales NSW Air Wing Information) and police rescue, to close down the party.
Despite the huge police presence, no arrests were made. Police are now scouring CCTV footage to identify those who threw bottles during the incident.
The free party - complete with lasers, video installations and DJs over three floors - was advertised on Facebook and at dance music websites including www.inthemix.com.au.
Text messages were also circulated inviting people to the party, listing the address and encouraging people to pass the invitation on.
Assistant Police Commissioner Catherine Burn admitted that police "did not know" of the party until revellers turned up at the warehouse.
One youngster identified only as Daniel said part of the event's appeal was that it was illegal.
He said there was significant drug use at the party.
"Going against the grain, of course its fun," he said.
"Is it right? No. But is it fun? Yes."
The Daily Telegraph says the party was the eighth in a string of illegal raves held across Sydney known as "Channel" parties.
Others have been held at Sydney's Clovelly Beach, Artarmon and Alexandria.
Police have identified the owner of the warehouse, but were yet to interview him last night. It's not known if he was aware of the rave.
Partygoers posted comments online about the rave, accusing police of being too heavy handed.
One reveller, Wana3q, wrote: "If the cops just let the party go on then they wouldn't have had to shut down Parramatta Rd or deal with a potentially volatile situation. I feel it was a massive overreaction."