Duplicate content is the worst enemy for any blog and it can cost you a lot if google has found duplicate content in your blog. Your blog can either be removed from the search engine or your ranking can be dropped for all your targeted keywords.
As you know TechMaish is a guest posting blog where most of the posts are contributed by the guest bloggers, internet marketers and business owners. I alwayscheck articles before publishing on my blog, because now a days most of the people are hiring writers to write articles on different topics to publish it on guest posting blogs to get backlinks in author bio.
A article written by a freelancer has always the issue of duplicate content, because of excessive load on the writer. OR the quality factor can be ignored by the writer which makes the article unprofessional and promotional one. I also check the already published articles on regularly basis to check if any of my blog article is copied. I am using different tools to detect duplicate content and some of them are great tools available for free. Although the tools are free, but if you buy a premium package then you can get accurate and detail result for your searches.