Article Directory Started - Google Penalty

I started new articles directory using wordpress.

Google penalize article directory?

My friend suggest that google penalize article websites for publishing duplicate contents - authors submit one articles to more than 100 websites.

It is true?

Please give me full idea to setup large article directory. How to avoid goole penalty?

 

Hi!
On Google official blogs, there was never exactly told that duplicated content led to any penalty.
However, unique content is always very well rewarded.
Sometimes, we do not have got any control about, who copy our content and how they use it.
You will not get penalty for duplicate content but, you will not rank high, if there is a lot of duplicate content,on your site.

 

Better if you only choose maybe around top 20 or 30 article directories to submit, above all, the quality of your article that makes this campaign effective..

 

you will NOT get penalty by submission same content to 100 places, although you will not gain much

 

I plan to setup clear and quality article directory, but i have doubt about google penalty. If i get penalty, all my hard work is waste.