What popular online activity involves grouping individuals and organizations into clusters or groups based on their likes and interests?

social networking

Explanation:

Social networking involves expanding the number of social contacts by connecting to individuals that are like-minded so that you can keep in touch with each other via the use of web-based applications. It is used by individuals, groups and even organization are benefiting from the importance of social networking. It organizes people, groups, and organizations based on the interests and likes.