Fwd.Us, a nonprofit advocacy group created by Mark Zuckerberg and other big Silicon Valley leaders, is coming under fire for running ads supporting the Keystone XL pipeline, and another ad that criticized health-care policies championed by President Obama. The push, in support of three conservative lawmakers, is claiming to be part of a new approach by Silicon Valley to pass comprehensive immigration reform. Liberal groups like the Sierra Club have criticized the move and have questioned some of the big names behind the group, including clean-tech investor John Doerr, Bill Gates, and LinkedIn founder Reid Hoffman.