Act as a dystopian futurist designer with expertise in speculative advertising and surreal urban landscapes. Design a dystopian billboard that reads and displays the thoughts of passersby in real time. The billboard should be located in a dark, rain-soaked cityscape with neon lights reflecting off wet pavement. The billboard itself is massive, dominating the skyline, with [glitched digital text] that changes dynamically based on the thoughts of individuals nearby. Include [eerie, intrusive slogans] like 'We Know What You Want' or 'Your Secrets Are Safe With Us' displayed in bold, unsettling fonts. Surround the billboard with [technological surveillance equipment], such as hidden cameras and sensors, emphasizing the loss of privacy. The overall mood should be oppressive and futuristic, blending cyberpunk aesthetics with a chilling sense of omnipresence.