Remember, it must be persecution....not the inability of Christians to use the force of government to spread the Word. Go ahead, Baptist. Tell me all about the Christians who are flogged and imprisoned in America for practicing their faith. I'm sure you have hundreds of stories, don't you?
A general definition for "persecute" is "to oppress or harass with ill-treatment, especially because of race, religion, gender, sexual orientation, or beliefs."
Oppression and harassment take different forms. Sometimes it is physical, but not always. I would consider it to be mildly oppresive if, in order to receive a passing grade in science class, I had to regurgitate atheistic talking points. I also consider it to be mildly oppresive to have my taxes used for the establishment and maintenance of atheistic science in public schools with no legal means to present the reasonably scientific assumption that the universe is a product of intelligent design. Lastly, I would consider it to be oppressive if atheists were given failing grades in science class because they happen to hold no belief in God.
Bottom line is, there is plenty of good science to do without making an issue of the observer's philosophical underpinnings.
Yes, there are real cases. Do you want to know, or do you only want to be snotty? We agree with you. We don't use government, and want government to stay as far away from us as possible. That is not what I'm talking about.