Apparently we're OK to sell thru cafepress. As long as we do not infringe on copyright, we'll be fine. All the art is and will be from scratch, and we're against a product* not an individual or group of individuals (protected or otherwise).
Maybe we can't suggest that Lotus Notes of a bag of crap, but we are fine with somewhat less offensive claims, and no infringement on "Lotus Notes" the trade mark in respect of products. We're fine under 'right to parody' I guess. And if we get a letter asking us to stop, IBM would know as well as we do that we'd publish it and bask in the attention.
We'll be loading more merchandise in time for May 13 (Intl Notes Hater Day).
* We expect that products will be elevated to be protected under the constitution shortly.
