Don't Conduct Large File Transfers Through a USB Hub!

TL;DR:

1. NEVER transfer large amounts of data to an external device over a USB hub--can lead to drive corruption!
• In fact, just try to avoid plugging external drives into USB hubs altogether.
2. Sometimes corrupted hard drives lock themselves down into a read-only mode after corruption to protect themselves from further damage.
3. Don't try to read the last directory you were copying over before the drive got corrupted--Windows Explorer could hang.
4. The files on read-only drives are still recoverable and you can copy them over to a new drive (but you'll probably have to skip at least a few unrecoverable corrupted files).
5. You can't/shouldn't try to make a corrupted drive usable again, at risk of more data loss. One clear indicator of a truly unusable drive is if "phantom files" remain on the drive after wiping/formatting it with 3rd-party tools.
• You may have to assign the drive a drive letter after wiping/formatting to see your drive's file contents.

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Story Time

I hate how few USB-A ports are on my MacBook Pro Late 2012 (on which I'm always running Windows/BootCamp). There are 2 USB-A ports (which is better than current-day MacBooks' USB-A counts, which is 0. Ugh). More frustrating still, there are these dumb Thunderbolt 2 (a.k.a. mini DisplayPort) ports taking up space where I feel there should be more USB-A's. So, to add more USB ports to my setup, I used a Targus ACH124 USB 3.0 hub for a while without issue.

However, during a backup project involving some massive file transfers to hub-connected external drives, I ended up killing a good-condition 32GB micro SD on the 1st day of my transfers, and then killed a good-condition (only-few-months-old) 1TB external HDD on the 2nd day. (Why did I try a large file transfer again on the 2nd day after I had already fried my MicroSD on the 1st day, you ask? Well, I thought the MicroSD failure was due to the card's age; I hadn't narrowed the problem down to the hub yet.) Turns out, according to this Amazon review, frying drives is a known fault with this particular hub:

Pathetic. Also turns out, it's an accepted fact that file transfers to drives connected through USB hubs can lead to data loss/drive corruption, particularly by means of voltage spikes or "brownouts," caused by insufficient power to the drive. (I imagine brownouts are the cause of both of my drives getting fried. I wouldn't be surprised if that dinky USB hub was unable to provide a steady stream of sufficient power to keep external drives running in peak condition during massive file transfers, without risk of corruption/data loss.)

Luckily, the contents on the 1TB external drive were still read-only, so I therefore could copy them to a new 1TB drive. (I just had to be careful to not attempt to open in Windows Explorer the last directory that I had been copying before the drive fried: That folder seemed to be the epicenter of the HDD's disease, and Windows Explorer hung when I attempted accessing it.) The MicroSD was a total goner, though: Formatting through Windows wouldn't work, and 3rd-party wipe & format programs failed to erase the "phantom files" left on the defunct card, even after wiping and writing over the card with the highest security setting and highest number of passes possible on MiniTool Drive Wipe [DoD 5220.28-STD (7 passes)].