No, not really. It's a rough estimate; given that the "Rape statistics" page on Wikipedia you reference puts rape attempts on women in the US at 1 in 6 (meanwhile, the same article puts rape attempts on men in the US at 1 in 33, largely accounted for by prison rape), adding in sexual assault, street harassment, etc can only increase that number. And 1 in 4 is a meaningful thing to visualize. Think of four women you know.

I'm not claiming that for the statistic for the US at large is 100% representative of the tech community. But unless you have a good reason to believe it to be different, it seems like a reasonable starting point.