The star, who is in the UK to promote her new film A Million Ways To Die In The West, made the comments when she was asked by Sky News if she ever googled herself.
She told the channel: "I don't do that, so that's my saving grace. When you start living in that world, and doing that, you start I guess feeling raped."
Asked by the interviewer if she felt that strongly about the issue, she said: "Well, you know when it comes to your son and your private life. Maybe that's just me.
"Some people might relish all that stuff but there are certain things in my life that I think of as very sacred and I am very protective over them."
South African-born Theron, who won the leading actress Oscar in 2003 for her portrayal of serial killer Aileen Wuornos, came under fire online for her comments.
One Twitter user said: "she should try telling that to a real rape victim" and another said: "how stupid to comment about press intrusion the same as being raped. Makes my blood boil!!"
Twilight star Kristen Stewart was forced to apologise when she made similar remarks in 2010 during an interview with Elle magazine.