Any site that does this, does this for a reason. Verizon does this as a service to their customers. Other sites do this to gather active cell phone numbers.
Why would you spend thousands of dollars a year to maintain a website, and pay to have this service provided free? Instead, you can harvest millions of cell phone numbers, and then sell them to companies that make a living by calling and harassing.
Now, you can spend 10 minutes and learn how to text with your phone, or you can sign your friends personal information up on the public domain - it all depends how you chose to treat your friends. Personally, I chose not to share my friend’s names, addresses, email or phone numbers with the public, and I drop friends who feel that I do not deserve the same consideration. Of course, you are free do do whatever you chose; just be aware that some may hold you accountable for your actions.
Which is why I posted the question.
I would prefer to protect my friends, thanks.