The tabloids are having fun with the fact that we have discovered no less than 5,000 new virus species in the ocean...and a new phylum.
So, time for a reminder:
Not all viruses are evil.
We have our own personal virome and while we don't understand the role of all of them, we aren't sick all the time.
Not all viruses are pathogens just as not all pathogens are viruses.
Our virome includes:
Potentially pathogenic viruses that we're currently living in harmony with, such as herpes.
Bacteriophages, which infect either our beneficial bacteria or the bacteria we need to keep under control. In short, there are some viruses in your body right now preventing you from getting sick by slowing the reproduction of certain bacteria and keeping your biome balanced.
"Passengers," which are viruses that are using us to live in, but aren't making us sick. Whether any of these are "paying rent" by providing a service is not entirely clear, but some clearly do. If you have hepatitis G, which doesn't always cause disease, it will help you by keeping out AIDS. (Yes, viruses fight each other). Herpes infection appears to be beneficial to the immune system.
Viruses that were infecting our food and aren't going to survive in us for long, which often means plant viruses.
And then there's the endogenous viruses which we've long since coopted, one of which is vital to making us what we are...
...the virus that gave us the codes to make a placenta.
The 5,000 new species we just found in the ocean aren't human pathogens. They're just a part of the ecosystem...just as some viruses are part of us.