This study explores how digital interface design—particularly through cookie consent banners and deceptive patterns—affects users' privacy-related decisions online. With the introduction of regulations such as the GDPR, websites are obligated to obtain informed consent from users before processing personal data. However, many employ design strategies that manipulate user behavior, often nudging them toward accepting tracking cookies. Drawing on a range of empirical studies and regulatory documents, this research examines both the psychological mechanisms behind users' choices and the legal frameworks intended to protect them. The findings suggest that design elements such as layout, wording, and visual hierarchy can significantly influence user consent, often undermining transparency and autonomy. Additionally, the study highlights the role of user knowledge and personality traits in privacy decision-making. Through a critical analysis of consent banners across multiple platforms, the research identifies recurring dark patterns and evaluates their compliance with legal standards. The study concludes that while current regulations aim to empower users, implementation gaps and manipulative design undermine those goals. It calls for stricter enforcement and more user-centered design practices that respect digital privacy rights.