I'm pretty sure you would be upset if someone came and built a house on land you own? This isn't about "Jewish" or "Palestinian" land, it's about respecting basic ownership laws, regardless of who the owner is. But it seems like if the (private) owner has Palestinian nationality then it's ok to walk in and steal his property.
UN to hold off on separate Afghan bombing probe for now (Reuters)
from the article: Netanyahu seeks to legalize outposts built on private Palestinian land