have any of these restrictions ever actually been enforced ??
It's not so much enforcement as a challenge basis. You're supposed to follow the rules and you are trusted to do so (via signing statements as above).
Technically you can't "domain" on .biz domains because it's not part of a bona fide business.
Search for:
Restrictions Dispute Resolution Policy
The Restrictions Dispute Resolution Policy (RDRP) applies in the unsponsored restricted TLD .biz. Registrations in the .biz TLD must be used or intended to be used primarily for bona fide business or commercial purposes. Challenges to a registration or use of a given domain name on the grounds that it is not being or will not be used primarily for a bona fide business or commercial purpose are filed under the RDRP. Challenges under the RDRP may be initiated by any party filing a complaint with an approved dispute resolution service provider.
Has it happened?
106124 us-bank.biz U.S. Bancorp Licensing, Inc. v Frederick W. Scalise, Ph.D. RDRP 3/29/02
112553 IPAY.BIZ Internet Billing Company LLC v Resource Marketing RDRP 5/9/02
137042 topdogsoftware.biz, topdogpro.biz DC Micro Development, Inc. aka TopDog Software, Inc. v Sophtware.com, Inc. RDRP 12/30/02
152121 red-cross.biz The American National Red Cross v TreeTops RDRP 3/31/03
155897 dana.biz Dana Corporation v Common Sense Enterprises, Inc., f.k.a. Swarthmore Associates RDRP 4/30/03
155901 centralpacificbank.biz Central Pacific Bank v Muhammad Aman aka CPB RDRP 5/6/03
250246 hp-cartridges.biz Hewlett-Packard Company and Hewlett-Packard Development Company, L.P. v Mario Dolzer RDRP 4/7/04
1306970 amarilloveins.com Ammar Jarrous, MD v Amarillo Cardiovascular & Thoracic Surgery RDRP 4/2/10
1337105 anzbank.biz Australia and New Zealand Banking Group Limited v Xirong Zhang / Rooholic International Pty. Ltd. RDRP 8/4/10
So not a lot
If .biz ever got as valuable as .com then things would change....
The reality is that you're unlikely to complain unless they are "squatting" on a name so it ends up being a UDRP/RDRP vs RDRP.
Basically, biz doesn't have enough value/presence to bother most people.
---------- Post added at 02:23 AM ---------- Previous post was at 02:21 AM ----------
Of course, Selling ad space is a Business .
Selling ad space and and using generated ads isn't the same thing. It's not providing goods or services.
But as mentioned above. No one cares. It's all unenforced T&Cs for the most part
Would make me think twice about registering a high value .biz as an investment; however. If it costs more than $2K then you're at risk of losing it to a complaint if it's just not used correctly and someone else wants it.