Let them look back into all their past life.

You look into someone's life, read where they have been and predict what will happen to them.

No one has the right to look into my private life.

They were looking into my private life in a way that had no relevance whatsoever.

Anyone looking into Liska's private life would have had a short glance at nothing.

"I thought that the progression of looking into her life would take about 10 years," she said.

They'd looked into my private life enough to know about him.

So I started looking into her life at the time.

You've got no right to look into my life like that.

On the other hand, it may be awkward for you to look into her personal life.