Most of Facebook's U.S. users have remained loyal to the social network despite revelations that a political consultancy collected information about millions of accounts without owners' permission, a Reuters/Ipsos poll released on Sunday showed.

Facebook has faced pressure from regulators, privacy advocates and shareholders since it said in March that political consultant Cambridge Analytica wrongly obtained personal data through a quiz app connected to Facebook. U.S. lawmakers grilled Facebook Chief Executive Mark Zuckerberg for two days on the matter.

The Reuters/Ipsos poll adds to other indications that Facebook has so far suffered no ill effects from the episode, other than a public relations headache.