- Are blue treemap your only value CBinsights? Well if you felt like you had to write about it, so maybe...
- Also public shaming using "Y Combinator company" instead of naming the company is shameful. Don't lump together all the YC companies for your own greed of getting attention.
- Your TOS blows. Close their account and send them a mail if you didn't want them to use your product.
http://bl.ocks.org/mbostock/4063582
Was it terribly uncreative for the other YCombinator company to do the same thing? Yes.
Was it plagiarism, copying, or unethical? No way. You did not invent the treemap nor a strong blue on light blue color scheme. Your UX is not unique enough to claim design infringement here.
Lastly, your TOS is probably the most alarming part of this story. You should not be so afraid of competition that you attempt to prohibit 'competitors' from using your product.