I never thought I'd say that I think aliens are more plausible than illegal miners with jetpacks, but uh... I actually think aliens might be more plausible than miners with jetpacks. I mean, there have to be more reasonable explanations than aliens or jetpacks, right?

"Miners with jetpacks" feels like something someone would say if they don't give a shit but are being forced into making a report. I just can't see a bunch of people who're mining gold illegally as being capable of rigging together jetpacks, nor can I see them having the money to buy one. Surely if they had the money to buy one then they could have bribed the right officials to make their illegal operations legal; and if they had the skills to make one themselves then I don't think they'd need to be illegally mining for gold.