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Yes, it will ask you for your posting private key. In any case, your funds are safe if you give only posting key. So no worries there.

thanks but it may not be a good mechanism. Not so many people is willing to provide private key.

@jimmyfotogallery thank you for your reply. Busy.org, dtube, dlive all require private keys, if somebody is not willing to provide them then he can't use these services. So you don't have to, but you might miss out on many things.