“Move fast and break things” has been the motto at Mark Zuckerberg’s Facebook, embodying the Silicon Valley ethos of unapologetically finding new ways to solve old problems. His latest foray into politics in Washington, however, might be characterized as “Move fast, play hardball and be prepared for blowback.”

Fwd.Us, the new nonprofit advocacy group created by Mr. Zuckerberg and several technology executives and investors to push for an overhaul of immigration law, has bankrolled television ads endorsing the conservative stands taken by three lawmakers, prompting an outcry from liberal groups and a call to withhold advertisements from Facebook.

The uproar, some say, will be a lesson for Silicon Valley companies as they try to influence emotional political issues like immigration. But the group’s supporters brashly say they were ready for the reaction.

“Our advertising decisions are being made by a very smart team of political operatives who know that passing major reform will require some different and innovative tactics,” Jim Breyer, a venture capitalist with Accel Partners and a contributor to the cause, said in an e-mailed statement. “I’m proud to support Fwd.Us as they work to pass comprehensive immigration reform.”