What are the cons of using Credit karma? I'm fine with them showing me as many ads as they want on their own site. But I'm not sure I want them giving over my a

What are the cons of using Credit karma? I'm fine with them showing me as many ads as they want on their own site. But I'm not sure I want them giving over my address and phone number to other parties who can then send as much spam as they want. Anyone have extensive experience using then, or knows all the fine print?