Should I make my domain registration private?

When you register a domain, you can choose to make your contact information public or private but what are the advantages and disadvantages to this?

When you register a domain name, whether or not it's a personal or business site, you're asked to provide personal information. You can either publicly register the domain, which is what most people do, or you can privately register it. A public registration allows for anyone on the web to do a WHOIS search for any domain names you own, and the search results will return your street address, e-mail address, name, and any other information you've entered in. A private registration hides all of that information, but it can have certain drawbacks as well.

Should I make my domain name private?What is the advantage?

Private registration was designed to protect your personal information, so if you don't want any spam, it's a great way to prevent it. 

What are the drawbacks of private domain registration?

Depending upon what you're using the domain name for, there are different pitfalls. If it's a business website, then it's a drawback because that's one less contact point. If you're just using it for a personal page, though, it obviously protects you from spam e-mails and people harassing you to sell your domain to them. For domain resellers, private registration can put you out of business because others will have a hard time getting in contact with you to buy your domain.

Regardless of the use, private registration could have a negative impact on SEO or get your site blacklisted. Combined with other red-flags, you can be labeled as a troublemaker. Also, human-reviewed web directories may be wary of adding you if you're not publicly registered.