Someone living along the Ganges River in India recently received a gift that we can safely say no one on Earth had ever gotten before. At first, it must have looked like an ordinary plastic bottle floating down the river, save for the rod poking out of its top, like a sailboat with a mast but no sail. The giftee, who remains anonymous, must have gotten curious and ripped open the 500-milliliter bottle, finding that it was in fact packed with electronics. Those included a SIM card, which the person popped into a mobile device and then logged into Facebook.

“The reason we knew it was in use was when we got the bill,” says Alasdair Davies, a technical specialist at the Zoological Society of London. You see, Davies, along with conservation scientist Emily Duncan of the University of Exeter and other researchers, had not long before released the bottle and nine others into the Ganges as part of a clever experiment to show how plastic pollution moves through rivers and eventually out to sea. SIM cards allowed the ill-fated bottle and its companions to connect to cell towers every three hours as they journeyed down the river, recording in great detail how far and how fast the devices traveled. One sailed 380 miles over 51 days.