Final answer:
Businesses can restrict access to content by requiring product registration and verification, while access may also be restricted by external factors such as censorship in certain countries or regions.
Step-by-step explanation:
To restrict access to knowledge bases and articles based on products owned by customers, a business can implement a system that verifies product ownership before granting access. This could be achieved through a secure user portal where customers register their products. Once a product is registered, the system can unlock access to associated resources and articles, ensuring only legitimate customers can access the content.
In an environment like an internet café in China, customers' access to information may be censored based on government policies. Therefore, certain topics and resources might not be available. In comparison, libraries in academic institutions such as the State University of New York library system provide access to vast databases of scholarly articles where reference librarians can assist in constructing effective searches with the right keywords.