Why are third-party cookies considered a major privacy concern?

• A. They are faster and cheaper to implement
• B. They can collect extensive information about users without explicit consent and persist across multiple sites
• C. They are stored locally and never shared
• D. They require explicit opt-in every session

Answer: (B)

Third-party cookies enable cross-site tracking. They are set by domains other than the site you’re visiting, usually by advertisers or analytics providers, and they follow you as you move between different sites. This lets those third parties collect detailed information about your browsing habits, interests, and even behaviors across many sites, often without you giving explicit consent. Because these cookies persist over time, they can recognize you across sessions, building a long-term profile. That combination of cross-site data collection, potential persistence, and limited visible consent makes them a major privacy concern.