The author likely used quotation marks around the word "they" to indicate a generalization or to imply a distinction between a specific group or entity (such as website operators or organizations) and the broader concept of the audience or visitors to the website. The use of quotation marks can suggest skepticism or encourage critical thinking about who "they" are—bringing attention to the idea that the intentions and practices of these entities may not be transparent.
In this context, the author may want readers to consider who is behind the website, what their motives are, and how they handle personal information, prompting users to be more discerning about the sources they trust and the information they share online.