TexasCHLforum.com

I went to the site, and before I could even scan the pages, I had to answer a popup which said the following:

TERMS OF USE

1. I am 18 years of age or older.
2. I understand that ARMSLIST DOES NOT become involved in transactions between parties and does not certify, investigate, or in any way guarantee the legal capacity of any party to transact.
3. I am responsible for obeying all applicable enforcement mechanisms, including, but not limited to federal, state, municipal, and tribal statutes, rules, regulations, ordinances, and judicial decisions, including compliance with all applicable licensing requirements.
4. I will not use Armslist.com for any illegal purpose.
5. If I am at all unsure about firearm sales or transfers, I will contact the Bureau of Alcohol, Tobacco, Firearms, and Explosive at 1-800-ATF-GUNS and visit the ATF website at http://www.atf.gov" onclick="window.open(this.href);return false;.
6. I will help to ensure the overall openness and accessibility of the site to all users through a peer-review process. I understand that failure to adhere to proper internet protocol and etiquette may result in removal of my listings or more severe corrective action.
7. ARMSLIST may edit or remove information, including my listings, from the site without notice.
8. If I violate these terms, ARMSLIST may permanently remove me from the site or, depending on the nature and severity of the violation, avail itself of such remedies as are prescribed by law. Whilst ARMSLIST ABSOLUTELY BELIEVES AND CHAMPIONS "the right of the people to keep and bear Arms," ARMSLIST will comply with federal, state, municipal, and tribal law enforcement entities pursuant to the Constitution of the United States and Due Process of Law.
9. I take responsibility for my actions whilst using Armslist.com. I also take responsibility for any and all of my actions related to, or resulting from, my use of Armslist.com. Further, I am solely responsible for any and all consequences of such my actions.
10. I indemnify and hold harmless ARMSLIST and all of its owners, directors, officers, employees, and agents for any and all loss, harm, damage, costs, liability, and expense caused to them, whether intentionally or unintentionally, by my use of Armslist.com, including but not limited to direct or indirect results of violations of any and all applicable laws.
11. ARMSLIST may make changes to these terms at any time without notifying me. As a user, I am solely responsible for reading the most current version of the terms and conditions.
12. By clicking "I agree," I electronically represent ("sign") that I agree to the above terms and further certify that I have read, and completely agree, to be legally bound by the ARMSLIST Terms of Use

Did your friend "lie" in order to view the sites pages? If so, he would lie on a 4473. ArmsList does not advocate doing anything illegal. In fact, it makes it plain in their rules that you may not do anything illegal.