This is something that's always perplexed me. Companies copy other companies' business models and compete for the same customers all the time, but that's considered fair game. But if a design is copied, shit hits the fan.
Frankly, I'd rather someone copy my design and go after a diff niche of customers than copy my product and come after my customers.
To the guys at Curebit - ignore this noise. The focus should be on creating an awesome product, getting paying customers and generating profits. You guys have an awesome product and deserve the funding. Congrats :)
P.S. You should remove the hotlinks tho. No need to use their bandwidth.