Judith Johnson of Stacyville, Iowa, doesn’t get out much anymore.

Legally blind and living on a small Social Security pension, the 72-year-old used to go to church once a week. She stopped out of fear that her new walker would snag on the railroad tracks she had to cross to get there.

But Johnson, whose tiny apartment is decorated with crucifixes, still believes it’s her duty to help those less fortunate.

So when telemarketers call on behalf of cancer patients, homeless veterans or disabled firefighters, the retired secretary finds it hard to say no.

That penchant for giving made Johnson the target of America’s billion-dollar charity fundraising industry.

In one recent year, callers persuaded her to write 25 checks to 11 different charities.

The repeated calls were no fluke.

Each one can be traced back to a single source — Associated Community Services, a Michigan-based company that is one of the nation’s largest charity telemarketing firms.

After Johnson gave to one charity, the firm put her on a list that got her bombarded with calls for nearly a dozen more company clients. Telemarketers sometimes called several times a day.

Johnson told one phone solicitor she couldn’t afford to give to a charity called Children with Hair Loss.

“She said, ‘You’re going to let this poor little child be bald-headed when they’re only 4 years old?’ ”  Johnson recalled. “I really felt bad for the children, so I think I gave her around $10.”

Unbeknownst to Johnson, about $1.75 of that donation made it to the charity. The telemarketing firm pocketed the rest.

The Center for Investigative Reporting and the Tampa Bay Times have been covering this story and others like it in their joint investigative series called America’s Worst Charities. Click here to read the full story about Johnson and this billion dollar industry. 

Don’t get fooled by bad charities. Here are some things you should know before you give this holiday season.