All donations are anonymous and sometimes even the donor doesn't know the sperm bank-assigned number. In order to find a donor, offpsring have to have a birth date for the donor and try to figure it out. Only with that number can offspring definitively find their donor fathers on the DSR, and many say it takes a lot of sleuthing.
Sometimes, truth is stranger than fiction.
One donor, Dr. Kirk Maxey, 52, of Michigan, said he may have sired at least 400 children after donating semen twice a week between 1980 and 1994.
"But he's nothing but another donor," said Kramer. "We have donors who have found 30-50-70 kids."
Sperm donors make about $1,200 month, donating three times a week for many years. "But that doesn't mean there are three potential children," said Kramer. "Every sample is broken out into eight to 25 vials for 75 potential children every week he donates."
Maxey has called for statutory rules for genetic tests of donors to prevent passing on inheritable diseases and volunteered to be part of Harvard University's Personal Genome Project. He already has reunited with two daughters through the DSR.
FDA guidelines indicate that donated sperm cannot have any "relevant communicable disease or agent," but there is no limit on how many donations can be made by one person or any sharing of medical information between the donor and the child's family.
Maxey is also critical of the "commercialism," of sperm banks that make greater profits by dividing up a single ejaculate.
"Make sperm distribution a mandatory non-profit activity, matching the status of all other traffic in living human tissue," said Maxey. "Disclose to all women all that is actually known about their prospective donor, and maintain a strict registry so that the knowledge base will be substantial. Make the information supplied by donors to banks legally binding, and obtained under oath. Make donor records indistinguishable from other medical records, but require them to be maintained a very long time – I suggest 100 years would be a good start. Make them discoverable and subject to HIPPA."
To date, more than 28,000 people -- donor men, parents and offspring -- have registered and more than 7,500 have found their half-siblings and biological fathers.
Now, many at the center of this storm are calling for an end to anonymous donation, hoping to model government-sponsored programs in Australia, Britain and some other European countries to identify sperm donors.
Tim Gullicksen, a 43-year-old real estate salesman from San Francisco, donated for a decade after signing up as a college student at Berkeley. He said he was promised only 10 families would get his sperm but now, "it's pretty clear there are 80 or 90 kids out there."
"These kids don't know me from Adam," he said.
The first child to contact him three years ago through DSR was a 9-year-old boy in Texas whose single mother had chosen sperm donation.
"He had five years of stuff for me when I met him and right after that everything started to snowball," said Gullicksen.
"He had been pestering his mom about where his dad was since he was a toddler," he said. "He had no father figure and he actually kept a box under his bed where he kept all his school projects and wrote 'Daddy' on the box."
Since then, Gullicksen has connected with seven children, ages 9 to 16, who hail from California, Texas, Chicago and North Carolina.