Plug a few leaks in the dam and a new one opens.
But at least two pretty cool games are back on the PlayStation Network, so that's a plus. Some time ago, hacking exploits were discovered in MotorStorm: Arctic Edge and Hot Shots Tennis for the PSP; these exploits allowed the somewhat clever to run unsigned code on the new PlayStation Vita.
As a result, Sony took down both titles to fix the issue and according to The Escapist , both the aforementioned games are back and available for download. Sony has provided us with firmware version 1.67, which effectively closed the exploits. However, while Wololo.net can confirm that Sony has fixed those games, the site has located yet another PSP title that lets hackers into the Vita. Which one? Well, they're not saying right now…
But it did let them get Doom running on the Vita, even after the PSN 1.67 update. Looks like Sony has another hole to plug, and maybe a few others they don't know about.