Well, the first couple of times is when I would post a bunch of pics from Comics Alliance's weekly best pics articles in the Awesome Pics thread. I just thought it was good art that others would like to see and it linked to the artists' sites so you could see more of their work.
Some posters would complain about it all that time saying things like I worked for CA or the pics weren't awesome enough. One even went so far as to make a thread specficily for me to post the pics only. I didn't post in it nor did I report it to any moderators, but it was locked pretty much right away. I told them if they didn't like what I posted, put me on ignore.
The other complaints happened when I posted frequently in the Cosplay thread. This was back when the forums didn't automatically resize big pictures. So, I was told to put spoiler tags on pics because they helped the thread load faster. Didn't see the big deal, but I did. Then, I was later told that they didn't help the thread load faster. So, it didn't matter.