a question about liens

[Jason Richey]

Say a property has a lien on it, now everybody collectively say "don't buy it", but jokes aside if a seller can sell a property with a lien on it then what real threat or problem does a lien pose? If I can buy it with a lien on it then can't I just turn around and sell it while ignoring the lien too? I don't have a property in mind, it's just a thought I was pondering and couldn't figure out what a lien actually does.