It does happen often, I've seen clients of mine suddenly hit with thousands of fake inbound links from garbage sites, Chinese sites, etc. I'm a relatively small fish so if it's happened to me I'm certain it happens on a much larger scale. I can't see how any one particular company could be singled out and blamed. There is the burden of proof, and without an actual credit card transaction or some other form of evidence how could anyone make that claim and have it stick? There are literally dozens of companies on the internet right now where, for $25, they will go out and spam the internet using software/bots to any link/text that you request. I'm sure there's no verification that you're the actual owner of the website when this is taking place. Since anyone can do it to anyone else, it's best to stay on top of what's going on for your clients but don't worry about it too much. Any time I have seen this happen I've always notified the client with a brief status update that something is going on. From the standpoint, mostly, of making sure that the owner of the company or an employee is doing something stupid without my knowledge.
