Google Ads allows for 500 IP exclusions in your campaigns and you'll notice that we use all of them. This is intentional.
If we identify 100 bad IPs in your ad campaigns, then we fill the remaining 400 with the most abusive IPs reported globally. Sites such as http://iplists.firehol.org/ provide a repository of blacklisted, fraudulent, and abusive IPs and we import those, via API, to your exclusion list to help reduce fraud proactively.
You can view the excluded IPs in your Google Ads account in your campaign's "Settings" tab:
If you have existing IPs in your Google Ads account that you would like to continue excluding from your campaigns, you will need to copy those and past to your "IP Blacklists" in your Fraud Blocker dashboard.