Actually from what I gather it is quite easy [sometimes] to adopt and a birthparent never even know. This is particularly true with birth fathers. In our adoption case (with my now adopted son) the absent birth parent was willing to sign and so it was quite easy. I have heard of many cases though in my research down the adoption path where the adoptive parents did searches with the OAG, DMV (as mentioned), used paid internet investigator searches, and even hired PI's then presented the evidence to the court and had the TPR signed. The truth is that none of those routes yield astounding results necessarily. I don't agree that the birth parents (the fathers in particular because these are the ones that it usually happens to) are being treated fairly but it does happen. Hmm, I guess they aren't really being treated badly they are just not being found. Maybe they don't even know? And, of course the cases I'm aware of are dealing primarily with step-adoption because this is what I'm familiar with being that it was my situation. Judges are far more leniant in these cases I imagine because at least one biological parent is present. I don't know for sure but it would be my guess.
Now if you wish to go it alone, there are ways to do so. One such way is to utilize the services of a Do-it-yourself adoption service such as RapidAdoption.com. For a reasonable fee, the fine folks at RapidAdoption.com will complete all of the necessary paperwork for the adoption in your state. They will even do it if the child is in a different state than you. They have been doing legal paperwork since 1998 and have prepared 1000’s of legal documents in all 50 states. But their service is only available in the United States and only with domestic adoptions. So if you reside outside of the United States or are adopting from another country, then this is not an option for you.