Last month, I noticed that my article got plagiarized and I emailed the website admin. After waiting for about a month, the plagiarized article got deleted by the admin and here is the email that I got from them,
Hi
Thank you for bringing this to my attention. On behalf of Helium I’m sorry that this has taken place. We do not tolerate plagiarism and I will delete the article right away.
Regards
Katie, Helium
Thanks for their support! 
[tags]plagiarize, article, helium knowledge[/tags]
nice to hear that. By the way, what service do you use to detect article Plagiarism. Mind sharing?
i just use google alert. each times there are new search results in google about phrases that we search, google will send an email. then i check the links given one by one.