It's an incomplete phrase, waiting for you to finish the sentence with the people you're crying for. For example:
* Je pleure pour ceux que j'aime. (I cry for those I love.)
* Je pleure pour ceux que j'ai perdus. (I cry for those I have lost.)
* Je pleure pour ceux que la guerre a touchés. (I cry for those who were touched by war.)
Let me know if you'd like help with a complete sentence!