Agreed, double-bluff. And in this particular case (Kent Systems), although it is addressed to the end-user, the bcc is the dealer, and it seems it was not really designed with customer guidance in mind, because:
We have over half of the statement glowingly giving the pitch for (and to) to the dealer:
Keri Systems products are sold through a network of installing dealers. In addition to being highly trained in security systems installation, they also provide a valuable service to the customer by being readily available to answer questions, provide support for hardware and software questions, or troubleshoot system problems. These services are often not available from an Internet-based seller.
But without any teeth it wouldn't mean much to the dealers, so we have:
Any sale of products by an unauthorized Internet-based seller voids Keri Systems Warranty on all products. Keri Systems believes that many Internet resellers do not fully disclose the risks associated with buying security products over the Internet. Please use caution when selecting your source for Keri Systems.
Which would be great if it weren't for the fact that there is no actionable guidance given.
Say I'm a customer reading this what would I think? Are all Internet based sales unwarranteed? No, only unauthorized ones. And though "many Internet Resellers do not fully disclose the risks", that implies that there are many who do. So general caution is advised. No list of unauthorized websites (like Dahua) or reseller names, no internal number to call to find out, no given way to tell waranteed product apart, etc. All consistent with a policy that is most likely, loosely enforced.
So what do you do? You ask the Internet Seller, "Is the warranty on this good?" :(