"It's always interesting to me when people build on top of a service that is free with no guarantee of it existing in the future." 1. free 2. no guarantees T

"It's always interesting to me when people build on top of a service that is free with no guarantee of it existing in the future." 1. free 2. no guarantees Think of a web site that is free to access, e.g., one that lets a user query a web crawl or a database of user-submitted personal photos, that also sells ads to anyone wanting to buy. "Customers" are allowed to buy ads, but how far into the future? Can the web site change its terms at any time? Can you think of an example?