As a tip to make reporting easier, examine them first; their character name will be at the top of the window. Then, even if they warp away, you can still open up a window to report them because their name will be right there for you. If that makes sense.
Alternatively, simply type "/echo <t>" while having them targeted.
I've seen a few, but the last couple gathering sessions I've had seem to be only legit players, but given how the ones I did see were all naked, I doubt endlessly mining level 30+ nodes is terribly time efficient even if automated. I can definitely see why the temptation is there, however. I'd rather the individual mining process take a bit longer than a simple click, but instead get you'd get more than 1 yield. I've started seeing nodes with +1 yield bonuses, sure, but 1 in 4 doesn't really expedite the mining process. I'm also running out of wind shards from my crafting, so the plan is either to farm those directly or sell other things to buy a restock.