Well, not really. Sure, social networks has its pros and cons, one of them is privacy. Not just Facebook, but even MySpace, Friendster, Orkut, etc. It's not Facebook's fault why some people are being stalked, and become vulnerable to identity theft, it's the responsibility of the user. If you wouldn't want strangers searching for your home, then don't place your real address. I have heard many cases of women being victimized on Facebook by being blackmailed for casual sex. They add them as friends even if they don't know them. Chat with them, even being convinced of giving their nude pictures to persons pretending to be someone else. Then being blackmailed of posting the nude photos if they don't agree to have sex with them. Of course, some persons will blame facebook for that! But the real one to blame is the person's gullibility, of trusting a total stranger who she hasn't met before. I have to repeat, the user is the one responsible for his/her privacy on social networking sites. If you don't want strangers to see your real address, facebook has the option to hide it, or don't even put it. If you don't want them to see your birthday, then hide it from your profile. If you're not comfortable with these privacy settings, chances are you didn't care to read the TOS of the site. It's very simple, if you don't agree with their TOS, then don't sign up.
Flash games are a good way to relax during your break, especially while your using your Facebook account. Many companies earn their living by charging gamers money for the playing their games. This is especially true for MMOGs. Even other games cost money, like Street Fighter, Tekken, etc. You have to purchase them before you play them. But in multiplayer online games, the game is free, but you have to pay everytime you play. But usually, games in facebook are free to play. If you want an advantage against other players, you may opt to buy game credits in exchange for in-game items. And that's optional. You aren't required to do so. Of course they would persuade you to buy game credits. It's called marketing. It's the reason why companies place ads on TV, radio, newspaper and even online. It is to earn money. They won't be able to give their developers their salaries if they don't earn money, unless they're philanthropists. But in the end, it's still up to you to buy them. They can persuade you, but they can't force you. And again, if you don't agree with their ways, you can always leave them. You don't have to stay with them. You can't blame facebook for having a crappy and untrustworthy game. You also can't blame the companies if they persuade you to buy game credits, it's their business. It's like blaming a hamburger for making you fat. You don't blame the hamburger because it's juicy and smells good, you blame yourself for giving in.
There are also advertisements on the right side of a page on facebook. These are 3rd party advertisements and Facebook has nothing to do with them. Facebook is not to blame if the advertisements contain scams, although it is Facebook's fault for not checking advertisements first before putting them live. This is also true for other online advertisements. You can't blame google for an irrelevant ad, you have to blame the one that create it. With the millions of advertisements being created everyday, you can't expect them to filter all of them, right?
In conclusion, I think your post pertains to the weaknesses of all websites and not just social networking sites particularly Facebook. Personal security is an issue that's being addressed even long ago. Before the advent of social networking sites, people create their personal homepages where they usually put a page called "About Me" where they put their real name, birthday and other personal information (imagine geocities, tripod and angelfire websites back in the 90's). It's almost the same with today, the only difference is that all user profiles are in one site. The point here is that you as the user must be responsible in putting sensitive information on the web. Be careful of what sites you visit. More malicious websites exist outside of facebook.