Any blog post with copyrighted material may be taken down. Because of this, please only use images labeled “royalty-free.”
Here are some websites where you can find these types of images:
If there’s a copyrighted picture that you would like to use, please make sure to credit it properly for the least amount of risks.
Here’s a great TAJ blog post where the author left proper credits for the featured image of the post: Fanfiction: The “Joke” of the Writing World.