Maelcum is the pilot of the tug ship Marcus Garvey. Originally, his job is to pilot the tug which has Case's console aboard, allowing Case to hack into the Villa Straylight's system. Later, he helps Case storm the Villa Straylight and provides care whenever Case flatlines. Maelcum even takes on a ninja assassin to help save Molly simply because he was moved by Jah's, or God's, love (16.48). The gist of all this is that this dude is one caring and courageous Rastafarian. Okay, yes, Molly wasn't in any real danger at that point, and yes, Hideo does soundly beat Maelcum, but it's the thought that counts.
Aerol is another Zionite tagging along with Case and Molly. He helps Case out while he adjusts to zero gravity and pilots the Babylon Rocker to support Maelcum's ship. Like most Rastafarians, he shows a distrust of technology and ideology from "Babylon," a distrust that extends to cyberspace (8.67).
What's all this Babylon stuff? Well according to Rastafari, Babylon represents Europe and America—the places where the people of Africa are exiled from their homeland. It embodies the ideals of slavery, greed, and corruption, and both Maelcum and Aerol just ain't havin' that. To them, cyberspace is Babylon, perhaps because it's become so pervasive and powerful in peoples lives. And when the corrupt elite—like the Tessier-Ashpools—have the ability to control cyberspace, well they're game to help anyone take them down, even if it means getting involved in cyberspace.