5. It's a necessity
Let's not forget that when it comes to patent law, companies have a responsibility to protect their intellectual property. So in some cases it makes sense that firms file suit as a defensive whenever they feel their patents are being violated. As with anything else, there are some that abuse rules and others that follow them. Right now, there are still many companies that are following them.
6. Similarities abound
It's also important for Google to recognize there is a lot of commonality in the mobile space right now. Multiple competing mobile operating systems have similar functionalities, devices look the same and the "feel" of the user interfaces of some of these products is quite close. Those similarities are causing some firms to jump the gun on lawsuits. Whether that's right or wrong is for the courts to decide.
7. There's a lot riding on the future
Perhaps one of the main reasons companies are so willing to be litigious right now is that they realize how important the mobile market will be in the coming years. Smartphones continue to gain popularity around the world and tablet sales are skyrocketing. Over the next decade, the mobile space could grow exponentially. So no firm-small or big-wants to be kept out of that money-making opportunity.
8. Google has a weak portfolio
Google has been targeted quite heavily by competitors, most notably Oracle, which is concerned about Android. Although Google might not like it, the company and its operating system have become lightning rods for lawsuits because it doesn't have as strong of a patent portfolio as it should. Other companies have a much stronger portfolio. And they smell blood. If Google wants to see the lawsuits stop, it'll have to buy more patents, just as it did recently with IBM.
9. For Microsoft, it's about vendors
As mentioned, Microsoft is trying to get Android vendors to pay it a "tax" for the right to sell their products. Although that's great for the short-term, Microsoft's eventual goal is to get those vendors to realize that it's cheaper to build Windows Phone 7 devices and ditch Android entirely. Whether it will work remains to be seen, but it's certainly possible.
10. The government hasn't stepped in
So far, government regulators and the courts have allowed companies to initiate lawsuits that, Google says, have no merit. Generally the government will let the courts decide these cases on their legal merits, unless Google can somehow show antitrust laws are being violated. But in any event, petty patent lawsuits aren't good for anyone, including consumers. If the lawsuits have no merit, it's about time someone steps in. However, so far, no one has done anything of the sort.