Accessing the source code of well-known technology companies usually involves legal and compliant methods. In addition to social engineering methods, the following are some common legal ways: 1. **Open source projects**: Many technology companies open source some or all of their projects. You can find relevant code repositories through platforms such as GitHub and GitLab. For example, companies such as Google and Facebook have open source projects. 2. **Developer documentation and SDK**: Many companies provide developer documentation and software development kits (SDKs). These resources usually contain sample code and API interfaces related to source code. 3. **Participate in hackathons or developer conferences**: Many technology companies share code and development tools at hackathons or developer conferences. Participating in activities can obtain relevant information. 4. **Technical blogs and documents**: Some companies share code examples, technical implementations, and architectural designs on their own technical blogs. 5. **Purchase a license or obtain authorization**: In some cases, source code can be legally obtained by purchasing a software license or applying for a specific authorization. 6. **Industry collaboration or research projects**: Academic researchers or industry partners who work with technology companies may be given access to source code in specific projects. 7. **Education and training courses**: Some companies share source code through official educational channels to help with learning and teaching. 8. **Public code review and security research**: Participating in security research, bug bounty programs, etc. may expose you to code from official channels. Please note that unauthorized access or disclosure of source code is illegal and may result in legal consequences. In any case, make sure to follow laws, regulations, and company policies.