Yes! Yes! Yes!…. I Mean No! – WWE taking legal action over use of Yes chant

I know the WWE has been involved in some bizarre legal issues over the years but if this is true then surely it has to rank high amongst them?
 
"WWE has started to seek out "infringing uses" of Daniel Bryan's "YES" slogan, so that they can take legal action."
 
http://www.411mania.com/wrestling/news/240978/WWE-News:-Richie-Steamboat-&-Dean-Ambrose-on-the-Road,-Sid-Vicious-Teases-Major-Appearance,-More.htm

I'm assuming the nebulous 411 report would be referring to their legal monkeys going after bootleg t-shirts and the like, since the YES shirt is a big seller, although I should note that 411 stole that report word-from-word from PWInsider without any context.  You can't trademark a word (like "Yes") but you can trademark a shirt design, especially if it's an easy one to rip off like Bryan's.  And really, even if someone is doing an innocent "Yes" shirt on Cafepress, WWE can easily bully them into stopping.  If that's what this is about, I'm on WWE's side for once — you have to protect your trademarks or risk losing them.