Fall into somebody’s hands/the hands of somebody
Definition 1 of 2
Pro Tip 1/3Implicit Power Shift
The phrase often hints at a power or control being transferred, sometimes unwillingly. 
When the CEO fell ill, control of the company fell into the hands of her inexperienced son.
Pro Tip 2/3Negative Connotation
It usually implies negative consequences if something falls into the wrong or enemy hands. 
We must ensure our plans don’t fall into the hands of our competitors.
Pro Tip 3/3Protective Urgency
The phrase can express the urgency of keeping something safe from others. 
The ancient artifacts must not fall into the hands of treasure hunters.