Can you not post full articles from other publications (blogs, news, etc) here on Tumblr? (Unless they were written by you). Yes, even with a link. s.e. smith has written about why this is a problem before, and done an excellent job, so I am just going to quote a couple of (fair-use) paragraphs from ou’s piece on the subject.
As a general rule, reprinting more than 50% of a post would be considered infringement in most cases. Whether or not there is a link back to the source. Let me say this again: If you reprint more than 50% of anything on this website, you are infringing my copyright. That is illegal. No matter who you are, no matter whether or not there is a backlink to the source, no matter what site you are reproducing it on, it is an infringement of my copyright. I would personally prefer that people reprint less than 50% of my work, choosing two or three paragraphs for excerpt.
When you infringe my copyright, you are actively hurting me and my livelihood. Given that some of the worst repeat offenders in terms of copyright infringement are sites that are supposedly organised to promote social justice causes…well. I find it odd that ‘feminists’ think that it’s ok to do this, let’s leave it at that, ok?