Many Dropbox users, over the past two days, have started to see spam from online casinos in their inboxes. Why is Dropbox being blamed? A particular user posted in a forum that the e-mail he only uses for Dropbox began to receive spam some 32 hours ago; the e-mail has never been listed anywhere else on the Web.

“So I guess you have a security problem with your user account data,” he wrote in his public forum post. “And this sucks a lot.”

As of yesterday night, there were over a hundred posts in the Dropbox forums reporting e-mail spam from online gambling sites sent to e-mails used for Dropbox. Mostly, these users are from Europe, centered around the U.K. and Germany.

The cause of the Dropbox leak is unknown at the time. Some believe that there may be a malware problem while others believe a spambot is randomly trying out e-mail servers to see if it can get a hit. TechCrunch stated that this statement was released earlier this day by Dropbox Associates:

“We’re aware that some Dropbox users have been receiving spam to email addresses associated with their Dropbox accounts. Our top priority is investigating this issue thoroughly and updating you as soon as we can. We know it’s frustrating not to get an update with more details sooner, but please bear with us as our investigation continues.”