Answer:
LinkedIn has a very smart algorithm, and it has a very strict policy against spammers. Back in 2014, it deleted millions of accounts that were causing spam on LinkedIn.
Spam occurs:
1. When you send bulk of connect requests in a short time
2. When you send irrelevant messages to prospects
3. When you Perform overactivity
4. When you use LinkedIn automation tools
5. When you send spammy and sales-y messages
All these actions cause spam on LinkedIn, and it immediately takes action against you by restricting your account temporarily or permanently.