The allegation a blogger laid out in a YouTube video seemed truly alarming — his smartphone was tracking his text messages and keystrokes, apparently recording his private thoughts. Voices in Congress immediately demanded answers from the cellphone service companies and the maker of the tracking software, Carrier IQ Inc.

Plaintiffs attorneys filed nearly 70 lawsuits, primarily against Carrier IQ and the manufacturers of the handsets, including Samsung Electronics Co. Ltd. and HTC Corp. The suits assert that the software violates the Federal Wiretap Act and additional privacy and consumer laws, and have been coordinated before U.S. District Judge Edward Chen in San Francisco. The first status hearing in the multidistrict litigation is scheduled for May 24.