This page attempts to answer the question, Why don't you try to find a technical solution for sexism? or for some part thereof.
See also Quick fix form letter.
The person you're asking is most likely a woman and most likely a geek feminist.
This means that she's a geek, and hangs out with a bunch of other geeks who are also interested in this issue. Many or even most of them are technical professionals, in fields ranging from cryptography to web app development to database theory. They are familiar with both the issue at hand (sexism, or part thereof) and the technology which would be used to address it if a technical fix were available. Despite this, they have not yet come up with a technical fix.
The reason for this is not that women aren't good at computers and need men to come in and suggest to them that they should try... USING COMPUTERS!!! to solve something. It is in fact that sexism is a bigger problem than that.
Your asking of the question is a variant of Splaining. You are being condescending. Go away until you have come up with a detailed, well thought out technical solution and had it reviewed by at least three experts in the field (not chosen for their geek-feminism or female-ness, because we're a bit tired of reviewing half-assed first tries at this) who can attest to it not being full of holes.
One of your reviewers should probably be a security expert, familiar with protecting high-visibility, controversial technology from attack by griefers. Another should be an investor who's going to fund the development of the solution, which means you'll probably want to make sure your solution will make money in some way. (Women are unlikely to feel enthusiastic about volunteering to work on the project for free. See Second shift.)
If you have done this, feel free to approach geek feminists with your solution. However, if your idea actually boils down to, "Gee, I bet those ladies haven't considered using technology for this!" then don't.
Database of women speakers
Been done, many times (see: Women speakers). The problem is getting conference organisers to use it.
Database of known harassers
See Database of harassers for a long list of concerns with the repeated proposal for a central database of harassers.
There are quite a few existing websites that identify harassers.
Spam spam something spam
This suggests that sexism is undesirable, like spam, and that surely we could use some of the same techniques to prevent it?
Spam fighting consists of identifying and blocking the unwanted material. We already know how to identify sexism, but stopping it requires widespread social changes -- considerably more difficult than applying a mail filter.
(Certainly, for certain kinds of online harassment, spam fighting tools are useful and are already widely in use. However, a regex looking for "feminazi" and similar terms only gets you so far. Much sexism uses subtle language and behaviour, or occurs offline where filters can't be applied. Check Timeline of incidents and consider which of these incidents would respond well to spam filtering techniques.) Have a look at the Talk: Technical solution page for some academic notes not yet integrated here.