Found this on another forum
There is a massive police operation setting up today around Olympic Park train station. There are 4 or 5 mobile command centres which suggests they are going to have the capacity to conduct strip searches. NB: I'm not condoning anything illegal but I reckon it would be VERY unwise to carry any "recreational" stuff if you intend to arrive via train.
You'd be better off catching the train to Concord West and walking through Bicentennial Park.