From the Terms of Use under Section "Intellectual Property Rights" Subsection "Counter-Notice":
"If you believe that your User Content that was removed (or to which access was disabled) is not infringing, or that you have the authorization from the copyright owner, the copyright owner’s agent, or pursuant to the law, to upload and use the content in your User Content, you may send a written counter-notice containing the following information to the Copyright Agent:
[...]
If a counter-notice is received by the Copyright Agent, Y Combinator will send a copy of the counter-notice to the original complaining party informing that person that it may replace the removed content or cease disabling it in 10 business days. Unless the copyright owner files an action seeking a court order against the content provider, member or user, the removed content may be replaced, or access to it restored, in 10 to 14 business days or more after receipt of the counter-notice, at our sole discretion."