No, you are not expected. It is just basic due diligence and logic to check up if the post that I support or engage with is not spam or plagiarism. Particularly when posts look like obvious plagiarism trash. There must have been like hundreds of thousands of similar spam plagiarism posts from newly created accounts. It is peculiar that after 4 years of being around, you are unable to just spot it right away. Your comment looks like you joined yesterday and have no idea what is going on around.