Originally Posted by kijakusai
has written that when he drew a scene in a manga, the editor 'called for a retake' because the scene included a signboard which had a trademark. Someone's comment on that message by Asamiya says that if a lawsuit is filed in such a case, it is possible that the rights holder of the trademark wins the suit.
I think that the manga and anime producers would not want to risk being involved in a lawsuit even if they thought that they could win it. It probably would not be worth the time and expense, and if the lawsuit delayed the release of future chapters or episodes that could be disastrous for the production company.
On a somewhat related note, I noticed that in K-On!
the musical instruments and equipment had the real manufacturer and models, such as Fender Mustang and Gibson Les Paul Standard Edition for Azusa and Yui's guitars, but other things used fake names. I think that Mio's tape player was a "Somy" or something like that.
I wonder if the producers got permission from the musical equipment makers. It would make sense to me that permission would be given since the show portrays music in such a positive way.
I also noticed that the K-On!
manga did not have any readable names on the instruments. Maybe they were just too hard to draw.