Yes. The risk is that Google could think that the content on your site is the duplicated one. Put a link on digg to your content to show which one is the original. But try not to post duplicated content, write a new one for digg or any other site.
I don't think there is a duplicate content penalty. Only the page with higher pagerank is displayed in results.
Now digg is no follow,so i think if you add your page in it,could increase traffic,not helpful of your backlinks.
Personally I wouldn't worry about traffic coming from the social bookmark applications. More than recently DIGG.com Has changed their webpage is to no follow attribute.................... a lot of the social bookmark applications like Facebook twitter are changing their algorithms to the no follow attribute so where does that leave me in you as far as traffic generation coming from these monsters social bookmark applications honestly that each of social bookmarking has died completely.............. how many of you would agree with this that social bookmarking sucks............
My short simple answer is NO. You put content in Digg BUT only a short snippet displayed while have a link back to your article as original sources. The link is nofollow but do believe me that Google still crawl and follow those link, just not give weight and PR leaked.
Unless your link gets on the first page of Digg it won't give you traffic. It DOES give you a quality back link and is well worth it.
i create upto 5 ID's on digg.com but i can't understand why they block my my ID's with all those pages that i socialy bookmark at digg. plz help me to solve the issue. i get alot of traffic from digg. kahanidesi..blogspot..com
Nope. Actually, it would be the opposite of what you're thinking. Search Engines(Google) will quickly crawl your site after submitting it to different high PR bookmarking sites like digg.
You won't be penalized for duplicate contents. But if you think that other persons stealing your contents, you can file a DMCA complaints.