If someone asks me to print them a poster with Taco Bells trademarked logo on it and they are going to hang it on their living room wall, is that illegal?
Scenario #2. If someone sends me a photo of them standing on a busy street corner and in the background are a dozen storefronts with trademarked logos from Nike to the NFL. Is it legal to print a poster of that?
I am not a lawyer, although I attended law school.
Copyright and trademarks are two very different legal areas.
If the poster art is not created by Taco Bell (or its ad agency, etc.) and you are not using it to sell food or commit any kind of fraud, you are almost certainly not infringing on their
trademark. (You could, of course, be involved a libel suit if you are ridiculing Taco Bell. That has nothing to do with copyright or trademark law, though.)
If the poster has already been printed by anyone, you are PROBABLY infringing on
copyright, unless the creator of the poster is your customer. In the US, copyright applies to anything written or imaged, even without the (C) symbol.
Scenario #2: This almost certainly falls within "fair use" from the copyright standpoint, so long as the pictures are the usual amateur shots with no commercial motives.
From a trademark standpoint, so long as you're not trying to sell anything by using the image, you're fine.
++++
Printer's responsibility on these matters:
Generally, the printer IS responsible in the US if it is obvious that the use or publication of the "intellectual property" (I.P.) can result in a loss to the owner of that "intellectual property". Loss of good reputation can be considered a loss. (Except for "fair use", which is a very interesting sideshow in the I.P. world. Suffice it to say that brief quotations and parody are almost always allowed.)
A very common example of this "loss" for printers and copy shops to keep in mind is duplicating the trademarked and copyrighted figures of Mickey Mouse or a Muppet or Spiderman onto birthday invitations.
This is a clear violation of copyright because the I.P. owner
could create the invitations and sell them at Hallmark for your customer to buy and have you imprint them. The I.P. owner is totally within its rights
not to choose to produce invitation cards (or tapestries, or anything else). That some poor little whimpering child could suffer grievously because of this is
not a valid legal defense.
Incidentally, I generally despise most of intellectual property law, especially the absurd length of copyright life. But I.P. law
does exist and has severe penalties, and it should be dealt with carefully unless you like courtrooms.