Why Block an IP Address?

There are several reasons a business, educational institution, or internet user would attempt to block an IP address

There are several reasons a business, educational institution, or internet user would attempt to block an IP address. In general, the most common reasons are:

• Blocking Bots, Spammers, and Hackers: When bots, spammers, and hackers attempt to infiltrate your website, it can put a heavy strain on your bandwidth and decrease the speed with which you and other users can access your website. If you run a business online, this can be detrimental to sales. 
• Limiting Website Access: Many academic institutions and businesses use IP blocking to limit the websites that students or employees can visit. The goal is typically to increase productivity by limiting distractions.
• Protecting Data: Hackers often attempt to infiltrate websites to steal data or other important information. That information can be used to blackmail or otherwise undermine a company.
• Maintaining Confidentiality: Many academic institutions and companies who keep sensitive records—like transcripts, health records, etc.—are regularly targeted by hackers. Identifying threatening IP addresses and placing them on a blacklist is an essential step to keep those records safe and confidential.

This list should only be seen as the tip of the iceberg. There are countless reasons that an individual or organization might want to block certain IP addresses, and there should be no underestimating how malicious certain internet hackers can be.

Source: https://www.domain.com/blog/2019/05/23/how-to-block-an-ip-address/