pipe to sudo -E bash -

It's a short way of executing a script without having to save the file and then execute it. When you save the file and then execute it, a number of things can go wrong:

• User didn't type the filename correctly
• User didn't use the correct shell (maybe ran sh foo.sh instead of bash foo.sh)
• User tried to execute the file instead of setting bash on it (./foo.sh), and forgot to set execute permissions
• User forgot to use sudo

By providing a single command line to execute, the developers can decrease the number of places where things can go wrong due to luser error.

Personally, I despise piping curl to bash. It's not safe.

This command would download file and attempt to execute it with root privileges.