Recent increase in spam form submissions - anything change?

[Anonymous]

Did anything change on Marketo's spam filter on forms/landing pages?  In the past 18 months, we never got a single spam lead in the system from a Marketo form.  Now, we're starting to see some small numbers of spam leads getting into Salesforce.com from Marketo forms.  These are full marketo landing pages.

Just wondering what could have caused the change to occur.

[Anonymous]

Nothing has changed on our end. More than likely these are from a new spambot or your page was recently discovered by an existing one.