Hello,
I go
here and see there are some
BTCitcoins sent from my adress.
But I never sent any
BTCitcoins (just receive). How is it possible ?
Is there something I don't understand ?
Thanks.
Are you using a hosted (shared) EWallet (e.g., Mt. Gox exchange, InstaWallet, etc.? If so then that address isn't your address, it just happens to be the address in which your account will be credited for any bitcoin deposits. So you will see funds leave but that is because the provider transfers funds around in their wallet, sometimes using the coins you deposited for the payout for other accountholder's withdrawals.
If instead you are using a local client like Bitcoin-Qt, Electrum, MultiBit, Armory, Bitcoin Wallet for Android or a hybrid EWallet like Blockchain.info/wallet, then you should never see a transaction that you did not initiate.