Are feral cats a problem?

The answer depends on your point of view and where you live. A lot of people see feral cats as a problem; usually a health problem. They say that feral cats spread disease and so on. Or the bird conservationists make exaggerated claims about how feral cats decimate bird populations. Some of these people have an axe to grind. They have a hidden agenda. Others are genuine. These people usually live in North America or Australia.

In the UK, feral cats are not seen as a problem and are often appreciated. We hardly see them. Throughout Europe the situation is probably similar.

In Asia there are lots of feral cats that would seem to be tolerated. In warmer climates feral cats are more visible and culled sometimes.

Feral cats have, in isolated cases, caused the loss of a high percentage of a single species of animal on small islands. 

There is a feral cat problem even if there is not a problem because a lot of people think there is a problem. This leads them to killing feral cats. Accordingly, for the feral cat, there is a problem - a big problem. An alternative view is that feral cats are beneficial but we don't know it.

It could be argued that we should be asking the question, "are people a problem?" People have created the feral cat problem.