To the best of my knowledge and experience, if a call is blocked, it is blocked period. Once a blocked number is identified as blocked, it is simply disconnected.
In iOS 13.6 there is no opportunity for the
blocked caller to leave a message creepy or otherwise neither does the caller get a message that their call was blocked. (But, there is an option in Settings > Phone to
Silence unknown callers and another option to send a text message of your choice and composition to
silenced, refused, or unanswered calls. So it would appear Apple has already responded to your request.)
However, it is possible for a
spoofer to place a call from a blocked number, or even
no number, and have it appear to your telephone as another number altogether. In other words the number that appears to be calling and you blocked has no relationship the actual number that made the call, and there may have never been actual telephone number.
While it is possible to identify
some spoofed calls, that is a continual running battle and requires full time teams of developers as well as extensive networks to identify and record suspect sources, just to stay even. Which is why there is a market for third party call blocking software such as NoMoRobo and MalwareBytes and why those products require a subscription to finance keeping their software and lists of bad numbers and urls constantly up to date.
Many, perhaps most, of these spam calls are marketing legitimate major institutions like AARP, VISA, Mastercard, major insurance companies,
etc. or at least companies that have contracted to market their products. So they are at least quasi-legitimate and carry enough influence with legislatures to prevent any laws against these practices with any real enforcement teeth. This is not going to change unless and until…
- there is universal agreement between almost all nations to solve the problem.
- there are enforceable international standards and controls
- the international telecommunications protocols are redesigned and rewritten to include security standards and a mechanism to enforce those standards and block non-compliant networks.
- the cost of violation is too significant to write off as a cost of doing business as usual.
- not likely to happen in our lifetime.
