No, unfortunately, they didn't use the same method as you. Some users here got confused.

Instead of them buying the actual US PSN Card or Redeem Code, which has this format (XXXX-XXXX-XXXX),
which they can use on their own PSN userid, they've bought "a shared PSN account" (the PSN Userid that already has been preloaded with limited amount of $).
 
What they do not know is, some of those "shared PSN account" are activated with "stolen" credit card numbers and  the fake seller tricked them into thinking that "shared PSN account" is good as any. The fake seller resells them to as many users as possible - therefore over-ran the number of machines that can download and install the games. When the last user tried to use it, he can't and begin the complaint and contact Sony or when the 'stolen credit card' gets reported. This is when Sony finds out and they will track the PSNs, IPs and MAC addresses and begin the shut down process.

Not only that, because the 'shared' account was activated using 'stolen' credit card info, Sony lost revenue because Sony gets a charge-back from the credit card company.

Sony will immediately shut off all the related 'shared' account because of this fraud. Imagine the horror, if you're given
your own PSN userid for fake seller to top up using 'stolen credit card', suddenly you lost all your privileges - including all your games contact, trophies, etc. That is why, some of the PSN userids are so cheap being advertised on Ebay or here (the fake seller never posts again after users complaint).

Also, sooner or later, when the pattern emerges later and if Sony finds out if majority of users from a certain region, they will ban that region from even logging in to US PSN network.

To be legit, I strongly advise users here to get a legit PSN Card or Redeem code that you can use on your OWN PSN userid.

Again, a real legit PSN Redeem Code has this format: XXXX-XXXX-XXXX. See my thread here for more info.

It is NOT an email address or password given to you so that you can login to download the games.

You should NEVER share your PSN userid with anybody (unless you truly trust your friends). 

Yes, Sony eventhough encourages games sharing (up to 5 registered machines) for friends and families but this privilege CAN BE REVOKED anytime. Do not abuse this. Once it is abused, the entire list of registered machines (via IPs or MAC addresses) will be banned.

Just to clarify those who are concerned.

If you have Asia console and you've purchased legally content from US or elsewhere, it won't cause your console to be banned.

It can be banned only if you've downloaded using the 'stolen' PSN userid that you have got from some unscrupulous dealer.

Sony scanned for those and if they found it using stolen PSN userids, that's the red flag. The games that you've downloaded will be deactivated. Your console may be even banned from using PSN (via MAC or IP).