Of course there are chances that other people might be able to steal your bitcoin. Always be careful on the websites that requires private information, especially those who asks for your private key or password, 99 percent of them are fraud or fake.
Good advice! Take this sentence as a proverb ; "Do not give your private key even to your father". It is very important, if someone get your private key then you are vulnerable to all kind of threats. Keep it safe, use 2 level verification and use hardware wallet if possible.