system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What mesures are taken in place to prevent foreign governments from intercepting/tampering with submarine fiber cables ?
gpt
The cable is thin and the ocean is large.

There are stories of secret submarines taping fibres at depth, but that's a hugely expensive way to get an unreasonably large stream of data.  What would someone do with that?  Any data that's even remotely valuable is encrypted.

There are concerns about denial of service attacks, and such attacks have happened (both on purpose and accidentally).  Maps show "no anchor" regions to protect cables, but an evildoer could use that information to cause mischief.  More cables in different places is the normal solution, or higher latency satellite links.