Spam accounts pose significant threats to platforms reliant on real users and clean data, affecting fintech companies, SaaS platforms, marketplaces, and social networks by causing fraudulent activities, skewing analytics, and creating compliance issues. Modern spam operations are sophisticated, using automation, disposable emails, and proxies to bypass traditional defenses like CAPTCHAs and IP blocking. Effective spam prevention requires moving beyond these outdated methods and implementing advanced techniques such as bot detection, email and phone verification, device fingerprinting, IP intelligence, behavioral analysis, signup velocity monitoring, real-time risk scoring, and machine learning detection. Platforms like Fingerprint use these techniques to generate persistent visitor IDs and Smart Signals, allowing for the identification and blocking of spam accounts in real time without disrupting legitimate users. Successful spam prevention involves monitoring, combining multiple signals, implementing graduated responses, and continually adjusting strategies to maintain platform integrity and support growth.