This is my website if anyone was wondering: https://freephonenum.com/

My competitor was scrapping all my phone numbers and SMS received from my site and displaying it on their site. It took me several months to figure that out. I was seeing abnormal bandwidth usage for JSON (my API endpoint) but never realized that someone was constantly pinging my APIs.

[edit] Now, I've removed the API and everything is served as HTML (not easier for someone to scrap my API)