Yes, it seems like you’re referring to a recent incident that took place on a bunch of Sydney beaches. Large numbers of mysterious, foul-smelling black balls appeared on the shores. Upon inspection, it was found that these were mini ‘fatbergs’. Fatbergs are often made up of congealed fat, wet wipes, oils, grease and other sanitary items that have not properly broken down in the sewer system. They can cause major problems in sewers and waterways, clogging up pipes and sometimes even bursting them. Authorities usually advise people to avoid disposing of these kinds of items down their sinks and toilets to prevent such situations.