Security concern is the more unlikely scenario of accidental cutting. There is enough redundancy that it is very difficult to cut them all for a single ship and if there are hypothetically multiple ships all cutting at the same time, then it is likely to be traceable. The cost of cutting these cables by sending someone out there is significant enough in addition to how unlikely they are to succeed.

It's by far the most common.. but.. Multiple cables in this manner is IME /less/ likely to be an anchor, although it has happened.

Cable cuts are very common worldwide and are very rarely reported widely in the media ( that I've seen ) unless there's an opportunity to tie it to Russia. Then it's reported as suspicious or there's a paragraph in the article speculating about the security implications of purposeful attacks on communications infrastructure. IMO it's a ploy to generate anxiety about how much money is being spent on "security" i.e. the military, and how we ( Europe ) need to increase it.

I meant they are intentional, as opposed to being a side-effect of ‘anchoring’ the boat to keep it from moving.

The chances of it being due to accident seems astronomically low, but I didn’t realize the intentional cutting was by an actual anchor. That makes sense though, as it would be an easy, discreet method.