Bulletproof hosting (BPH) is technical infrastructure service provided by an Internet hosting service that is resilient to complaints of illicit activities, which serves criminal actors as a basic building block for streamlining various cyberattacks. BPH providers allow online gambling, illegal pornography, botnet command and control servers, spam, copyrighted materials, hate speech and misinformation, despite takedown court orders and law enforcement subpoenas, allowing such material in their acceptable use policies.

BPH providers usually operate in jurisdictions which have lenient laws against such conduct. Most non-BPH service providers prohibit transferring materials over their network that would be in violation of their terms of service and the local laws of the incorporated jurisdiction, and oftentimes any abuse reports would result in takedowns to avoid their autonomous system's IP address block being blacklisted by other providers and by Spamhaus.