It's an anti abuse method. A valid phone number will always have a cost for spammers/multi accounters to obtain in mass, but will have no cost for the desired user base (the assumption is that every worthwhile user already has a phone).
Captchas are trivially broken and you can get access to millions of residential IP addresses, but phone numbers (especially if you filter out VOIP providers) still have a cost.
Re:Claude 3.7 Sonnet and Claude Code
by dist-epoch on Tuesday February 25, 2025 @03:46AM
(#43169592)
Just buy a $5 burner phone number. No need to use your real one.
There's also been a spate of AI companies rushing to release products and having "oops" moments where they leaked customer chats or whatever.
They're not run like a FAANG, they don't have the same security pedigree, and they generally don't have any real guarantee of privacy.
So yes, my privacy is more valuable.
Conversely: Why is my non-privacy so valuable to Anthropic? Do they plan on selling my data? Maybe not now... but when funding gets a bit tight? Do they plan on selling my information to the likes of Cambridge Analytica? Not just superficial metadata, but also an AI-summarised history of my questions?
The best thing to do would be not to ask. But they are asking.
Why?
Why only them?