Bitcoin blockchain is publicly available so anyone have your address can enter into the blockchain explorers and find the history of the address, remaining balance and all and to the extreme it is also possible to find the wallet ID and find all other addresses belongs to that wallet if I am not wrong. So if you don't want anyone to know your address then you have to mix the coins before sending for that lot of ways are available or simply you can send funds from an exchange so that they will never know your personal address.