No one actually knows how many kangaroos and wallabies are living in northern Australia.
So in 2005, young ecologists Euan Ritchie and Jen Martin got in a 4WD and set out on a roo-counting adventure in the spectacular wilderness.
Ten years on, and they started hearing stories from the local indigenous community that the marsupials were disappearing at an alarming rate.
So the intrepid couple set up a Pozible fund, hoping to raise $15,000 to go back to the tropics and see how the roos are faring, ten years down the track.
Only two days after launching their campaign, they got an email from Pozible. Someone had donated over $2 billion. They couldn't believe it, but it was right there on the page.
Here's the email Jen got from Pozible, with a $2147483647 credit card donation from Jeffrey Green.
But a couple of hours later, the $2 billion disappeared.
Jen and Euan say they have no idea who Jeffrey Green is. The mystery benefactor even claimed a prize worth $2000, which is more than had been donated to the whole campaign at that point.
A spokesperson for Pozible says they rejected the pledge because it was deemed suspicious.
"When we called it was a wrong number, which was a fairly clear indication to us that it wasn't a genuine pledge. We could also see that the person had tried to pledge twice with different payment options, but the same amount each time. They were pretty determined," the spokesperson told BuzzFeed News.
Pozible has since removed Jeffrey Green's account.
"That said, $2 billion is probably the most amount of money that's ever been pledged to a crowdfunding campaign ever, and we're a little sad we couldn't be part of making history!"