Oh, sorry about that. I was going to ask first since many forums have strict policies, but after looking around a bit, it seemed to me that the usage of copyrighted and even "ripped" content was generally accepted since no one's making a profit ("Maptools SNES Style" thread, for example). These screenshots are hardly ripped game assets, so I figured there'd be no harm.
It was also never outright condemned in the Posting Rules and Policies sticky; you guys might want to update that regarding this topic, as that's where I looked first and expected to find a definite answer.
In any case, I'll remove the images and try to be good in the future.