A BGP Hijack happens when another network announces your prefix without authorization, potentially causing traffic disruption or loss of reachability.
For IPv4 owners and lessees, routing security should be part of resource management:
Maintain accurate routing authorization
Use RPKI/ROAs where applicable
Monitor BGP announcements for your prefixes
Remove outdated authorizations when routing changes
IPv4 security isn’t only about who holds the resource, it’s also about who the Internet accepts as authorized to announce it.