See 10 Good Reasons Why You Should Block Someone On LinkedIn

1. They spam your LinkedIn inbox with marketing messages.

2. They use LinkedIn as a dating site.

3. They reach out to your contacts without your knowledge or permission,  representing themselves as a close friend of yours.

4. They use rude or inappropriate language.

5. Their LinkedIn profile is fake. The profile photo, name, job title and summary paragraph don’t correspond to one another. You can Google Search a LinkedIn user’s profile photo by right-clicking on it. It may be a photo swiped from an advertisement, or the portrait of someone famous the fake LinkedIn user is pretending to be.

6. They add you to their newsletter subscriber list and spam you to death.

7. They try to sign you up as an affiliate partner of their website — although you have no interest in the topic and have never suggested that you do.

8. They ask you to invest in their dubious project.

9. They want you to endorse them as an expert in some topic or other, although they know you have no knowledge of their work.

10. They creep you out, plain and simple. - Forbes