Power bank not allowed in Flight - Is it true?

There are certain rules covering Power banks. Generally, Batteries with a capacity of up to 100 W are allowed while boarding the plane. These are prohibited on planes from being carried check in baggage. You can carry them in the carry on bags.
In fact, the rules specifying the guidelines are carried out as long as batteries and power banks are quite ambiguous. And this causes a lot of confusion. There have been a few cases in recent times wherein passengers have been asked to collect the power bank and such items from the airport authority in 14 days. They were not allowed to carry it in either their carry-on bag or check-in bag.
As per the rules, the power banks are allowed in carry-on bags, while prohibited in check in bags, but exactly opposite is the case with the dry cell batteries. These batteries are allowed in check in bags, but cannot be carried in the cabin.

International flights have now asked passengers to not carry power bank in their check-in bags. You'll be asked to to put them into carry on bags. Also the phone chargers in some cases are not allowed as many flights have now provided the USB port that can take any charging point. Do note that international flight rules are set on region specific basis. US and EU being very strict rules, you may not find much strictness in Asian flights and they may allow you to carry power bank.

Domestic flights do allow you to the carry on chargers and power banks in the carry on bags. But even they don't allow the devices in the check in bags. Best option in such case is asking the flight crew before boarding. And then you can leave the devices with airport authority. Either you or your relatives or friends can collect them if you want.