How Spoofed Numbers and AI Evade Call Blockers
Why caller ID can be manipulated, what STIR/SHAKEN actually verifies, and how rotating numbers and AI-assisted voices make simple number matching less dependable.
Read articleJustBlocked Editorial · Call Safety
Understand the call before it gets your attention.
Research, field notes and practical guides about unwanted calls, caller identity, voicemail, privacy and the changing technology behind modern spam calling.
Featured · September 28, 2026
One year of building JustBlocked changed the question
Field report · Spam calls · Android call control
We Spent a Year Building a Call Blocker. The Number Wasn’t the Real Problem.
We started by trying to stop bad phone numbers. A year later, we were thinking about something bigger: what “blocked” actually means, why voicemail changes the outcome, and why the most reliable part of the system may be the phone you already control.
Read the field reportResearch library
Explore JustBlocked call-safety research
Start anywhere. Each article is written to stand on its own, with links into the related research when you want to go deeper.
Why Spam Number Databases Fail Modern Call Screening
Reputation is useful after history exists. This deep dive examines the gap created by new, rotated, spoofed and reassigned numbers—and what local policy can do differently.
Read articleCore Community Mission: Make Spam Calls a Dead End
Why private, independent call-control decisions can protect attention without requiring a centralized collection of everyone’s personal call activity.
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Why JustBlocked Is Different
A detailed look at local rules, Regex filtering, schedules, aggressive Answer + Hang-up behavior and the privacy-first architecture behind JustBlocked on Android.
Read articleHow we write
Useful claims. Clear limits.
Primary sources first. We prefer regulators, standards bodies and official platform documentation for technical or consumer-safety claims.
Observation is not proof. Product-development observations are labeled as such rather than presented as universal telecom behavior.
User control matters. We distinguish what a system can infer about a caller from what the phone owner can directly choose and enforce.