What kind of spider is this?

So I live in Northern California, about an hour of San Francisco. My friends and I were camping last night in an area with dry grass and a small patch of forrest. When we woke up today in said patch of Forrest we found tiny white spiders with somewhat long almost transparent legs. And there weren't one or two of these, they were EVERYWHERE! The ground, on the tent, but what they really liked was the mock mossy camouflage I put on the tent, I must of found at least fourth on those spiders in that alone. So what I was wondering is what exactly are these spiders? And are they poisonous? After researching I think it may be a Holocnemus pluchei, which is some sort of cellar spider that came to the U.S from Europe in 1970, but it almost doesn't sound right and only slightly looks the same, thanks!