Illawarra students are defying the Prime Minister's warnings to avoid the "planking" craze, photographing themselves in increasingly dangerous situations lying flat as a board and posting the pictures on the internet.The bizarre craze has shot to prominence over the past month, and last weekend claimed the life of a Brisbane man who was trying to "plank" on a seventh-storey balcony rail.In recent days employees from Woolworths and its subsidiary Dick Smith have been sacked for planking on the job.The "Illawarra Plankers" group has posted dozens of photos on Facebook, while two videos of Illawarra plankers have appeared on the video-sharing website YouTube.Many of the Illawarra stunts are harmless.A cabinet in a TAFE class is planked, one planker is lying on top of a children's carousel in the shopping mall at Shellharbour, a student spans the walls over a toilet cubicle at Figtree High, while students at Corpus Christi play it safe by forming a chain of planks on the grass.But others are more risky.One student, purportedly from Kanahooka High, is photographed lying on the crossbar of goalposts at the school's football oval.Another planker is seen lying on top of an old sign about two storeys above the ground at Warilla, while in another photo, a boy lies horizontally on a full-size basketball hoop at Oak Flats High.The students of Kanahooka High and Oak Flats High seem to be the busiest plankers in the region. Seven students have been snapped planking in a classroom at Oak Flats High.Most of the students' planks appear harmless.An education department spokesman said no students had been suspended from either Kanahooka or Oak Flats high schools for planking."Schools are overwhelmingly safe places, however, students who behave in any way that puts either themselves or others at risk of harm are liable to strict disciplinary action," he said.One post on Facebook warned people to keep it safe or risk drawing heat from the authorities."What's going to happen soon, though, is that some people will take it too far in schools and get it banned," it said. "That would be bad. So I am imploring everyone to stay safe and not to try anything too ridiculous at school."On Thursday, five days after 20-year-old Acton Beale plunged to his death in Brisbane, Prime Minister Julia Gillard warned against unsafe planking."There's a difference between a harmless bit of fun done somewhere that's really safe and taking a risk with your life," she said."Everybody likes a bit of fun, but the focus has to be on keeping yourself safe."