The same vendors that sell Linkedin data in bulk include this level of personal information (phones, personal/work emails, addresses). Perhaps this is how they mine the data they sell, but I think it's more likely they take use the information scraped from Linkedin and send it to other vendors to enrich it with personal information.

This is exactly what's happening. My phone number and email are being targeted now.

I've sent out hundreds of applications over my career and never had this problem until now.