How do headhunters get personal information?

There are actually many channels for headhunting consultants to obtain information, but these channels are generally common to everyone, and even ordinary people can get it if they want to know. The following basil net tells me how I got the candidate's information according to my headhunting experience of more than ten years:

1. Traditional recruitment websites: 5 1job, Zhilian, boss, etc.

2. Social networks: LinkedIn, Weibo, Twitter and personal blog.

3. Reference: candidate recommendation.

4. Unfamiliar phone: Unfamiliar phone, just answer it when you call.

5. Other channels: such as qq system recommendation, linkedin system recommendation, etc., and there are many skills.

6. List: obtained through candidate relations, friends in the headhunting circle and other channels.

7. Get offline social contacts: technical gatherings, etc.

From what he said is very mysterious, it may be social network or candidate recommendation, or the latest list, comprehensive understanding.