WASHINGTON (AP) - Facebook and Twitter executives say they agree with Congress that strengthening privacy protections for their users is a "national security priority."

Critics have charged that the companies' business models, which are built on offering a free service and making money from advertising targeted using personal data, can conflict with efforts to oppose those who would abuse their systems.

The Senate intelligence committee is holding a hearing on social media and elections. Oregon Democrat Ron Wyden says personal data is now the "weapon of choice" of political influence campaigns.