I came across this article last week, and I would agree that this is a less know scam that can start again since we are somewhat in a bull run. So the scam goes like this.
(a) pre-ordering mining gear with a promised of good performanceOne example of such a hardware scheme was Squirrel Research Labs, as initially promoted by Kristy-Leigh Minehan, aka OmgAGirl. This venture sold over a million dollars worth of FPGA’s, promoted as hardware that would be able to mine Monero.
Instead of Monero, this hardware was only able to mine a handful of altcoins. No one broke even on these FGPA’s.
I try to search the forum about this product,
Acorn M.2 FPGA based GPU Accelerator.
And if you go look at the very bottom of the page, it seems that they have pulled a scam here.
And here is the scam accusations
Acorn M.2 FPGA based GPU Accelerator-Considering legal action!.
The other project is Obelisk Inc, Lead by Siacoin developer David Vorick, and operated by Zach Zerbert, Ken Carpenter and Jacob Johnston.
And this is what I found out,
First Asic for SIA - Obelisk SC1.
Again you just have to look at the comments from more experience player in the mining like @Searing to understand that it is also a scam.
Then they try to salvage by launching a GRIN Asic miner, but it also failed obviously.
Obelisk Tech Grin Asics.
(b) Fork hardware wallet - we can't really trust them with our precious
BTC.
The same people behind the failed and scam Obelisk project re-invent themselves, created Coinkite which is a fork of an open source ColdCard wallet.
So what happened?
Coinkite Is Closing Down Its Web Wallet.
The full article can be seen here:
https://medium.com/coinmonks/rekt-crypto-hardware-con-artists-creep-into-bitcoin-8ad713198d3aAgain, this is not well-known but it doesn't mean that these kind of people are not going to pull this stunt again.