How Dangerous is Unfiltered Html on MU?

HI Guys,

I have been looking for a developer to help me with registering an embed handler for a few sites but have had not luck so far. I found "Unfiltered MU" plugin that allows all admins on my MU buddypress site to use embed codes in their posts from these sites.

However, I keep reading how dangerous this is and wanted to know is it really that dangerous? Also, this doesn't fix the fact that users can't share these embeds using buddypress activity plus unfortunately so I am still probably going to need a developer anyway. Thanks!