One easy way to prove once and for all its real....

Ownership of the block address

If they are mining coins, then they are finding blocks. Then those blocks's coinbase tx (vtx[0]) will contain their wallet address

They merely need to sign a message using an address found in one of their blocks to prove that they are mining.

Then, the block chain can be analysed, and a lot of those blocks should be found. They will 100% be able to provide all addresses for every coin they mine - as they will have received the coins.

This causes them 0 security risk and no personal information is required.

So.... Hashlets... PROVE YOU ARE MINING


note: If they are just trading money for money and "fabricating that people are renting a miner" - thats deceptive purchasing - and misleading the buyer is usually illegal. Regardless of whether or not people are making money from it.

Ultimately, if they are trading - and their trades are better than any multipool's payouts - they should just be honest about it.

Be like "pay us to make you more coins than you can mine anywhere"