Marlasmom, the scary thing is that anyone can call up the anonymous hotline and say anything, and the parent is automatically on the defensive. Before I forget, the unfounded report can be "expunged" from the record, but your daughter would need to get a lawyer and pay some sum of money to get that done. It would be worth it in case any other reports come in on her child (from the school, for instance). A "pattern" of unfounded reports is still considered a pattern, apparently. That is why it is so important to go after any malicious false reporters if you have the means to do so.
In the case of your grandson, the person called and remarked on his birthmark and another bruise. That was fairly easily refuted, as the birthmark had been there since birth and the pediatrician was supportive that there were no signs of abuse. However, any random person can pick a name out of a phonebook and anonymously make horrendous allegations about another person, and the falsely accused person is automatically put in the position of defending their right to parent their own child. As in that case in the NY Times, sometimes the children are actually removed on the basis of these false allegations, making the situation even more horrendous. Scary stuff.
The worst part is that while we have the means and the information with which to defend ourselves, many other people don't. This means that a lot of low-income people end up targeted by false allegations and are unable to defend themselves...hence my concerns about adopting from CPS. What looks like a terrible case on paper may actually be nothing more than false allegations mixed with a low income level. Things aren't always how them seem, and that worries me.