It's a pretty easy thing to do. However, since people want to sell things that say the word Phish on it to people who want to buy things with the word Phish on it...the trend continues. How many message board threads have you seen where people ask...'Hey can I get away with selling this??" Too many.
I think a great lot shirt or pin requires a bit of thought and execution. Anyone who has been doing this for a little while knows that there is a risk of the merch police confiscating your stuff. So, why not take the time to come up with an original concept? Dropping another word inside the Phish logo amounts to dropping a sports team inside a Steal Your Face. It's not original, and it's hardly a new concept. In fact, it's insulting. I will even go so far as to say it's hurting the rest of us. I have even seen a new trend of just blatantly using old Phish poster or sticker art. Really?
I have begun removing links from my store to any other site that uses these. If I have struck a chord with you and you disagree, feel free to unfollow or block me. At this point I don't care. What frustrates me the most is that I see talented people doing this. It's different if you are painting a piece of cardboard for a "Need Tickets" sign. These pins and shirts require investments of several hundred dollars at a time. You really aren't going to convince me that you are buying $400 worth of pins for heady trades.