When you did that Whois look up at the ARIN website, you did agree to terms of use for the Whois service which contains indemnification provisions and are legally enforceable. <https://www.arin.net/resources/registry/whois/tou/>

If you instead used a command line interface (e.g. "whois -h whois.arin.net …”), then you received output from ARIN’s Whois server along with notice of the applicable terms of service…  I would observe that continued use at that point has been held to indicate agreement on your part [ref: Register.com, Inc. v. Verio, Inc., 356 F.3d 393 (2d Cir. 2004)]

Thanks,

/John

John Curran

President and CEO

American Registry for Internet Numbers

Just like to add kudos to John for being open and responsive on this list and other lists to numerous issues and questions in regards to ARIN.  Not many CEOs are willing or able to respond as you do. 

Thanks for your time and effort,

-Hank