Thousands of Twitter passwords, user names and their e-mail addresses have been posted online, but there’s something strange about this particular data dump.

Details from more than 55,000 Twitter accounts were uploaded in five pages to Pastebin, the text-sharing site favored by hackers. But as CNet reports, something’s not right. Twitter spokesperson Robert Weeks said the data is not necessarily of high quality:

“It’s worth noting that, so far, we’ve discovered that the list of alleged accounts and passwords found on Pastebin consists of more than 20,000 duplicates, many spam accounts that have already been suspended, and many log-in credentials that do not appear to be linked (that is, the password and username are not actually associated with each other),” he said.

Twitter has automatically reset the passwords for the affected accounts. But you may want to change your Twitter password, just in case. And you can check to see if your Twitter name and e-mail address is on the list by clicking the links in this Airdemon.net blog post.

The strange nature of the list – in many cases the passwords, user names and email addresses aren’t linked together – has drawn the curiosity of hacker Adrian Lamo, who wrote about it on his Facebook account. He thinks the list may be from an older hack and posted now hoping to generate some news, rather than a breach of Twitter’s systems.

When a substantial vulnerability in account security is located, an intruder of even moderate intelligence will leverage it for maximum effect unless they’re playing a long game of monitoring the account or the network which it has access to. These accounts are – from the perspective of an intruder – pedestrian. They contain no e-mail addresses belonging to sensitive domains, they do not include Twitter staff, notably they don’t include me, quite possibly the most hated ex-hacker alive in the eyes of the hacker community, and they in fact seem quite random. I’ve seen lists like these before – and, without exception, fragments of this list are what I’d expect from a collection of phished passwords sewn together into a larger list, freshened up a bit to obscure their antiquity, and presented as something new and newsworthy.

Nevertheless, a little paranoia is always healthy when it comes to online security. Here’s how you can change your Twitter password.