vk.comは安全ですか？

Very slow reaction of the administration of the service to the distribution of spam, pornography, fraud, inciting scandals and other malicious and violating the laws of most countries (incl. website hosting country) content. Tech support is completely incompetent and can only answer simple questions. Support doesn't consider compliants about suspicious elements at all. There is not much adware, but it is relevant for you, so there may be a privacy leak. Personal information and uploaded content are not removed from the physical host, even on upon request to the support team. This website is definitely not for children.