Ask HN: Risks of using online developer tools

I am sure there is a clear security risks of using online tools like 1. JsonFormatter 2. YAML validator 3. SQL formatter 4. Image converter 5. PDF converter many more...

I am looking for real world examples/cases of security vulnerability/issues you/your company encountered. This helps me to make a case at my company to implement a company wide deployment of these tools(open source) as internal tools for developers to use.