Flow chart image not found

The flow chart image in the Drupal ladder for Getting started for GCI students, under how GCI works, is missing. There is a placeholder for an image linking to http://imagizer.imageshack.us/v2/800x600q90/823/sct8.png

Here is the link to the ladder: http://drupalladder.org/lesson/bd484d3c-5fc8-4aef-920f-66ddd3914992

Also, the images under Registering and joining Drupal are missing.

Here is the link to the ladder: http://drupalladder.org/lesson/68a836c3-1db1-4b1e-aa0b-c36b55de4d7f