The public documentation should never use this SSH based URL type for Github repositories, because this only works if the user has a Github account and linked his public key with that account. This is not necessary for public read-only access. So please ensure to always link to either the https or git read-only repository URLs. (e.g. https://github.com/cloudControl/java-jetty-example-app.git or git://github.com/cloudControl/java-jetty-example-app.git)

@mkorszun: Please check this for all other Java guides aswell.
@sfriesel: Please check this for all Python guides.
@ikusalic: Please check this for all Ruby guides. 
@MatthiasWiesner: Please check this for all PHP guides.