Random errors in computer hardware can result in bit flips that can be exploited by bitsquatters. While the probability of these errors is extremely low, with billions of devices connected to the internet, they present a large and increasingly viable attack surface. To take advantage of this exploit, attackers buy domain names that have a single bit changed and wait to intercept data intended for the target domain.
If people are served cached data containing a bit flip, they may inadvertently direct their traffic to a different domain than they intended and subsequently be served malicious code. For example, an operating system update coming from microsofu.com instead of microsoft.com could be devastating. To minimize these risks, use relative instead of absolute references to limit the probability of bit flips leading to users visiting separate domains that aren't under your control.