Is it safe to transfer shares to broker's collateral account to get margin?

I am asking about another discount broker.

I have my shares in CDSL demat account…I have not given POA of any type but whenever I want to sell I transfer to brokers collateral account (they call is CCA) via CDSL’s easiest facility because I have added broker as a trusted account.

Now I am considering options trading and they said you can transfer shares to same CCA (collateral) account and u can get margin fund after hair cut …they don’t charge any interest on margin against shares.

But since I heard some bad news about Karvy etc…I am wondering is it safe to transfer to their CCA account …(even though I have not given POA) they can still play games if they want?

For example once I transfer to them …they can do what ever they want with my shares for example pledge it further to get money for their own trading or even sell them and keep the money?

Currently, the way clients can avail margins with Zerodha in the F&O segment is by physically transferring shares from their own account to the account of the broker and then it gets pledged to the Clearing Corporation.

Effective June 01, 2020, this process is undergoing a change. The shares will no longer move out of the investor’s demat. Instead, a pledge will be marked in favor of the trading member. Here’s the SEBI circular explaining the change.

Yes currently the only way is to move from clients demat to broker demat (now they call it client collateral account) so once a client moves to broker’s collateral account …can he by any means misuse it? if yes what worse a broker can possibly do?