Here are SEVEN key questions that helps you decide wether what you have included on your website that were taken from others, is considered a fair use. Generally speaking, Fair use allows you to use someone’s copyrighted work without permission. If you are to use this material, it must must be for “purposes such as criticism, comment, news reporting, teaching, scholarship, or research.” AND “the use of this copyrighted piece should not be within a material that is used for profit-generation, and/or in a volume from that work that is considerable, depending on the nature of the work”.
So if your specific blog that you used a copyrighted material is fit with the first part of the above equation (for example, people don’t pay you to read that specific blog), then the second part applies, including, of course, wether you used the material in an ad rich site that will generate profit for you by attracting people to the copyrighted material. Interesting!!
The SEVEN key questions are included in this article that is clear and really easy to digest: https://janefriedman.com/the-fair-use-doctrine/
