We get these questions periodically. Unfortunately, content scraping has become popular again though there are fewer sites/people who are scraping sites. It is clearly damaging. It appears that Google has missed the boat on how important this is and has let loose of this issue of late. I am not sure why, however, you can find recent SEO articles on this topic.
There are several things you can do.
The first thing you want to do is create a canonical tag for each of your posts that points to the post. I suggest looking at this page: https://support.google.com/webmasters/answer/139066?hl=en and look at the header Indicate the preferred URL with the rel="canonical" link element for an example. This can potentially protect you in the future.
The second thing you want to do is file a DMCA complaint with Google for each case. This does two things: one, it makes Google aware there is a problem; and two, files an official complaint with the authorities that others can take action on. You can file that complaint here: https://www.google.com/webmasters/tools/dmca-notice however, you will need to create a Google Search Console (Webmaster Tools) account first if you do not have one. It is well worth the effort.
You can also contact the registrar and host companies. Many do not want to hear your complaint and say there is nothing they can do. But that is not true. These companies are liable if they reject your complaint and do nothing. See my next option.
Next, I would research the owners of these websites the best you can. If you are not able to obtain the site registration information due to private site registration, a lawyer can penetrate this for you. I suggest hiring a lawyer to at least write a letter requesting a take down. You should allow for 10 business days for a response or have the page to be removed. When the 10 day has expired and no response or action has been taken, your lawyer can file for a cease and decease through the courts. This is a simple process and is a court order that cannot be ignored and can be enforced in many countries. If this fails, you can file a suit which allows you to make very expensive requirements (for the offenders) with penalties if ignored. In the Google link above, Google quotes an award for $100,000. This will cost some money, however, a good lawyer can duplicate letters and filings and do this work for a reasonable rate using paralegals. Often, just a letter from an lawyer or a cease and decease notice is enough. As well, have the lawyer contact the registrar and host companies. Lawyers often do not get ignored and companies often respond to them favorably.