The Rock of Ages actor famously sued various tabloids, including The Daily Express, over claims that his marriage to Nicole Kidman was a sham.
In a new interview with Playboy, Cruise explained why he is so protective of his personal privacy.
"[The tabloids] know I mean it, that if I have to, I will sue," he told the magazine. "You start with a letter saying, 'OK, you know it's not true. Apologise'. There is a point with a lot of things when you just go, 'You know what? I don't want to waste my time with this. I'm busy'."
He added: "I'd rather spend this time with my kids and my wife, at home or on our movies, creating a life together. If you have kids, it is the most important thing to create good times."
Cruise also discussed the invasion of privacy that his wife Katie Holmes and children have endured.
"I put [privacy] in a minor pile of things I have to handle. But with certain ones you have to go, 'OK, you crossed a line, and now you have the attention of my lawyers'," Cruise added.
"When it involves your kids, with these guys you have to go, 'Here's the line, and anytime you cross it….' But there are lots of times when you just have to say, 'Please don't cross that line. Be decent. Let's not do this'."
Cruise and Holmes famously married in Italy in 2006, months after the birth of their daughter Suri.
The actor co-stars with Russell Brand and Catherine Zeta-Jones in Rock of Ages, opening on June 15 in US and UK cinemas.
Watch a trailer for Rock of Ages below: