As if tackling the malware economy wasn't already hard enough, police forces face a massive task keeping tabs on the 'darknet' of anonymisation services that are being used by criminals to hide themselves, Europol's latest Internet Organised Crime Assessment (iOCTA) has argued.
The report makes particular mention of child porn accessed through cloaking services - Tor, Freenet and Invisible Internet Project - but the same is true of other risky activities such as drug, gun and stolen data trading that seem to be migrating rapidly from the Internet to the mysterious shadowlands beyond the easy web address accessed from Google.
Tor - or more accurately the abuse of Tor - comes in for a bit of bashing here from Europol, hiding as it does an increasingly labyrinthine web of services ordinary Internet users never hear about, including those distributing what is known in the policing business as 'child abuse material' (CAM).
One could argue that so-called darknets are more off a convenience than a necessity because there are already plenty of other defensive tools in the criminal's arsenal. Full-disk encryption, VPNs, bullet-proof hosting and secure mail have existed for some time - Tor's popularity might be new but its anonymity isn't that much of an innovation.
In Europol's view the key to untangling this mess isn't more technology or surveillance but better global legislation to make such activities illegal. At the moment, criminals were able to evade arrest by exploiting the absence of laws in some countries or loopholes present in others.
"The inherently transnational nature of cybercrime, with its growing commercialisation and sophistication of attack capabilities, is the main trend identified in the iOCTA," said Europol director, Rob Wainwright, sounding a warning about the risk of fighting the issue on a country-by-country basis.
"It means that issues concerning attribution, the abuse of legitimate services, and inadequate or inconsistent legislation are among the most important challenges facing law enforcement today."
According to the report, police also needed to find a way to share investigative techniques and information on crimes, with Europol's own EC3 opened in 2013, forming an important hub.
Ironically, the whole scheme of synchronising international laws and policing bears some resemblance to the creation of Interpol a century ago, which explored the same idea for conventional policing.
"We need to use our new knowledge of how organised crime operates online to launch more transnational operations. We need to ensure that investigations into payment card fraud and online child abuse don't stop at national borders," echoed EU commissioner for Home Affairs, Cecilia Malmstrm.
On that topic, earlier this month Europol launched the Joint Cybercrime Action Taskforce (J-CAT) under a six-month pilot scheme to coordinate the agency's response to complex malware attacks that span borders.