According to a post by Twitter co-founder Biz Stone on the Twitter blog, the social-networking site's issues with this week's denial-of-service attacks aren't quite over yet.

TechCrunch reported on a post from the mailing list for Twitter's application-program-interface team, which read, in part:

As you know all too well, Twitter, among other services, has been getting hit pretty hard with a DDoS attack over the past 24+ hours. Yesterday (Thursday) we saw the attack come in a number of waves and from a number of different vectors, increasing in intensity along the way. We were able to stabilize our own service for a bit, hence Biz's post saying all was well, but that didn't mean the attacks had ceased. In fact, at around 3 a.m. PT today (Friday), the attacks intensified to almost 10x of what it was yesterday. In order for us to defend from the attack, we have had to put a number of services in place, and we know that some of you have gotten caught in the crossfire. Please know we are as frustrated as you are and wish there was more we could have communicated along the way.

Stone wrote on the Twitter blog:

In the past 24 hours, we've been contending with a variety of attacks that continue to change in nature and intensity. We're working to restore access to apps built on the Twitter platform that were affected by defensive measures—there was some overcompensation on our part as we tune our system to deal with this scale of attack. The ongoing, massively coordinated attacks on Twitter this week appear to have been geopolitical in motivation. However, we don't feel it's appropriate to engage in speculative discussion about these motivations. The open exchange of information can have a positive impact globally and our job is to keep Twitter services running reliably to the best of our ability.