Access to VK methods without authorization

Question

PHP

Hello.
The site turboliker.ru organized the receipt of user data without authorization. That is, the entrance to the site is implemented in this way: we enter a link to our profile in VK, we are given a link where we need to put "I like it", if we like it within 10 seconds, then authorization occurs on the site. In fact, no application needs to be installed, and we can receive any information about the user.
For example, we subscribe to a group from the list, the system checks if %username% is subscribed to the group and charges him some account balance.
How is it implemented without authorization? According to the official documentation, you need to make an application, moreover, it must have rights with a bit mask (For example, find out subscribers: vk.com/pages?oid=-1&p=subscriptions.)
Thanks in advance for the information.

Answer 1

VK has many api methods that do not require authorization.
+ they can get a list of "likes" of some page with their own token. your permission is not required.

Answer 2

OAuth API .

Answer 3

Getting data by id api.vk.com/method/users.get?uid=1 In
general, many methods from the vk.com/dev/methods page are available without authorization. Including a list of likes and a list of subscribers.
It is more difficult with friends - you need to prepare tokens in advance and store them in a variable.