I own 1/3 of a company, with two other founders who own 1/3 each.
We're approached by a company that wants to buy us, and they offer a deal that my co-founders jump at but I'm not so sure. I now need to "fend off" the takeover by convincing my co-founders not to see the deal through. This is especially troublesome given they have a majority between them. If there are more than three shareholders or more complex company structures (such as a company that previously raised a round of investment and has a group of investors looking to get out) then more possibilities come in to play.
Let's then go on to assume that the (hostile) takeover isn't successful. The buyer could seek opportunities in my marketplace to make my business less valuable. They might purchase a competitor who was previously smaller than us but is then provided the capacity and financial resource for growth that we do not have.