Here is another example of toll fraud. Likely the most common and financially significant voice, VoIP, UC security issue. Perhaps the nastiest thing about toll fraud is that while it affects all enterprises, it often affects smaller companies, that just don't have the time and expertise to secure their systems. Small companies can generate a lot of toll fraud though.
It isn't clear if this is DISA (dial through fraud abuse) or IRSF where calls were automatically generated to premium numbers.