I'm not encouraging or condoning this in any way, but I will admit that I have bought a few of these cards in the past. My PSN account is fine and the downloads still work. I kinda figured these people found a loophole aswell. I'm hoping that's truly how they got the $$$ in these accounts, because if it's from stolen credit cards then that's just a shame. I won't be buying any more of these, and I don't suggest that anyone else here does either; if these are from stolen credit cards, then it's not worth what could happen to you in the long-run.
From experiences of buying these cards, I can say that some of these guys are honest and will send you the PSN account details. Some of them will try and run off with your money. It's just a matter of trying to find someone who will actually send you the information. I've only had one bad egg out of three. I bought the first one to see if it was actually real or not, and it is. The second one was to get the DLC for Borderlands and other games (this was the one that ran off with my money). The third guy came through and I got Borderlands DLC with it. Beware if you're planning to buy one of these.
Also, I'm new to this site so I'm not sure if I'm allowed to link out of here or not but... If the link gets deleted, just search "150 psn" or "150 playstation network card" or something of the such. You'll surely find loads of them.
ALSO, one more thing. Off of eBay, I purchased MW2 last week. When my copy arrived (brand new I might add), it had a Walmart receipt in the packaging. The receipt showed that all this person did was buy the game off of Walmart.com, put in MY shipping address and have it sent to my house. I only payed them $39 for the game. The receipt showed this person payed a total of $67.11 for this game ($52.54 for the game, $9.97 for the shipping and $4.60 tax).
This was NOT mentioned in the auction and I was pretty surprised when I first got the game and receipt. I almost shat myself with thoughts like: "Oh crap this person stole a credit card, bought this game and got it sent to my address... I'm screwed." But after calming down and thinking about it, I figured it was probably someone who got a Walmart giftcard for christmas/from contest/giveaway or whatever and decided they wanted to get cash out of it rather than buying shit from Walmart.
Hopefully that's how it turns out. But in a worst case scenario, where the police come knocking on my door, accusing me of credit card fraud... I've saved the receipt, where it shows the person who ordered the game's address. I've also saved a screenshot of the auction I won just incase. I hope this person bought this game legit, because if not... He's screwed.
Anyways, just of the story is there's something fishy going on. Whether it's stolen credit cards, loopholes or whatever... People are making profit through shady businesses. I advise you all to steer clear of these cards and watch what you buy eBay.
This is just one example of the many sellers of these cards. This guy is selling them for $13, but you can find these things for as low as $10, easy. The people who sell them for $10+ on eBay have a method of buying them for $5ish in mass numbers and resell them. So in reality, these guys are just making profit off of the original sellers (god knows how the original sellers got the cards). So, depending on how you look at it... These guys are kinda the drug dealers of the Playstation world