Don't get it twisted. You built a pretty box that happened to house pirate goods. These companies don't owe any of us something for that. Ops don't have "the right" legally or morally to exploit other people's hard work.
It's an extremely safe bet that they know about these things. Game industry people are...*shock*...video game players as well. It's just...well..."bigger fish to fry" as others have said. If these were pretty boxes with mod'ed consoles and a harddrive full of 360 games, you'd be hearing from these people really quick...or you'd be keeping things much more on the down-low.
It really goes back to the mighty dollar. Namco and Nintendo are both litigious in going after folks for infringement but most of the time it's not worth it. A C&D letter is going to cost you about $200-500 (guess) in fees to execute and if they want to scare someone to shut down, The letters are carbon copy but often times it's actually hard to research and figure out who and where the operator is. They also need to send foot soldiers out to find infringements in the field. They won't see any of those dollars back. The best they can get is to have customs seize stuff at port. The problem with 60:1 cards is that they look really like video cards and not arcade bootleg boards.
Namco and Nintendo will go after you for art issues also but they are mostly protecting their brands at that point. It's hard to justify legal dollars for a marketing department in that sense. Namco had a lawyer on staff that specifically went after people that infringe but then again that's hard also. I think that the guys thats that sell boards via a website do start to fly into the radar of these publishers. Anyone openly selling a 60:1 on a website my run into issues sometime as these boards are so cheap now ($75 or less if you go dirrect to asia) that they are going to be pumped out in great volume. I'm sure that publishers know about these bootleg boards but where are they loosing sales? Only Namco liscenses still their games for arcade use. Pacman Party is sold in limited use and is the only comparable product to a nicely buillt 60:1 multi.
I personally suspect that a kit to produce one of the Namco 25th LCD machines could do really well. LCDs have a standard mount pattern to bolt from behind if someone build a case (roll down mech option on the side) with metal control panel that locks from the back. Cheap powersupply ... people can put these cases together and then supply a 17" 4:3 monitor for this thing. Instant product for people that just have to supply a 60:1 and a LCD monitor. Sell skinned side art and you have an instant hit.
