It is never really safe to put personal information out there via the internet or in the hands of any company or organization.
I very much avoid any extraneous accounts beyond basic checking and savings. Do not use debit cards either.
No problem with other people doing so if they have a real need and the service/account serves in some manner not otherwise available.
And I am always concerned about the associated User agreements which very much favor the provider over the customer. And the provider can pretty much changes the terms at will. And you may not even notice or realize it because of all the fine print....
Minimize what you provide and always keep an eye on your account(s). At least scan any documents sent to you either...