The Internal Revenue Service official overseeing the unit that targeted conservative groups for several years beginning in the spring of 2010 has been placed on administrative leave, according to congressional sources in both parties.

The Internal Revenue Service official overseeing the unit that targeted conservative groups for several years beginning in the spring of 2010 has been placed on administrative leave, according to congressional sources in both parties.

The Internal Revenue Service official overseeing the unit that targeted conservative groups for several years beginning in the spring of 2010 has been placed on administrative leave, according to congressional sources in both parties.

After a series of high-profile and embarrassing hacks, Twitter has rolled out a new, two-step login to help users prevent unwanted intrusions.