Senator Charles E. Schumer has never struggled to find a reason to hold a news conference on a Sunday. But the inspiration for the one on Mother’s Day arrived unexpectedly, when the senator’s cellphone rang during a health care meeting on Capitol Hill last week.

“You are still eligible to reactivate warranty coverage,” said the recorded voice on the line. “This is the final call before we close the file. Press 1 to speak to a representative now about your vehicle.”

Most people react with annoyance as soon as they hear the insistent  and all-too-familiar  voices and simply hang up. But, then, most people cannot investigate who is behind the call and take the information to the Federal Trade Commission.

Mr. Schumer said he received the call on Wednesday as he discussed national health care issues with two other senators, Blanche L. Lincoln of Arkansas and Debbie Stabenow of Michigan.