There is a lot of dispute about that on here.

From where I stand, I do not see it as a problem if full credit along with links back to original source are given. This is done in the news reporting industry all the time with local papers using Reuters.

Steemcleaners will hit those posts up in many instances so it is something to be mindful of. However, steemit.com is close to being a top 600 site in the US and top 1800 in the world. This means that the backlinks carry a good deal of weight and actually help the other site (if it is rate lower). Plus, there is always the chance of getting that site some additional viewers.

@zer0hedge on here created a lot of controversy with doing that same thing. Personally I support what is put up (mostly because I like the stuff posted) plus it is fully disclosed that it is not the site itself posting, the author is clearly stated, and links are provided to the site.