To implement data loss prevention (DLP) and restrict user access to social media platforms and personal cloud storage, the company should deploy content filtering. Content filtering examines the data being transmitted over the network and can block specific types of content or websites based on predefined policies. This type of filtering is effective in preventing access to specific web services and ensuring that sensitive information does not leave the network through unauthorized channels. Port, DNS, and MAC filtering serve different purposes and are not as effective for DLP in this context.
Reference: CompTIA Network+ Certification Exam Objectives - Network Security section.