Skyhigh Networks is shining a spotlight on cloud usage trends and the riskiest behaviors and services currently being used by its more than 3 million end users. According to the "Cloud Adoption and Risk Report," which is based on actual usage rather survey data, organizations are currently suffering from a lack of consistent policies to manage security, compliance, governance and legal risks associated with cloud computing.

According to the report, collaboration, social media and file-sharing applications are dominating the top 20 list of cloud services. Although many are consumer applications such as Facebook (FB), Twitter and YouTube, some business applications are ranking high, as well, including Amazon (AMZN) Web Services (at No. 3), Microsoft (MSFT) Office 365 (at No. 7) and Google (GOOG) Apps (at No. 10).

Of even greater interest is how frequently cloud services are being blocked and which ones are at the top of the IT department hit list. Cloud services including Apple (AAPL) iCloud (No. 3), AWS (No. 6) and Dropbox (No. 8) all made the list.

But unfortunately, IT departments and their trusted providers are frequently only seeing the trees and missing out on the forest. Low-risk cloud services are blocked 40 percent more than high-risk services. Part of the reason for this? Kamal Shah, vice president of marketing at Skyhigh Networks, told Talkin' Cloud that IT managers are frequently blocking the most popular "risky" apps while completely ignoring much riskier apps.

For instance, Dropbox is frequently on the IT to-block list, but the even riskier RapidGator is usually wide open and still in regular usage by end users.

"They're acting based on what's popular, not based on what's the greatest risk because they just don't have visibility into what's being used by all their employees," Shah said.

Also of interest is how different some heavily regulated industries are in the way they block risky cloud services. Take health care as a good example, which has a much lower blocking rate than the equally regulated financial services industry.

Organizations could also do with a little consolidation in some areas. On average, each Skyhigh network customer is using 19 different file sharing services, which Shah said impedes collaboration. Some of the file-sync and -share cloud services are vetted and approved by IT, but others are being used secretly and without such approval. Either way, it's problematic, Shah said.

So with all of the various types of cloud services on the market, what is the most blocked category? It may be a little surprising. Backup and archiving earns that honor and is blocked by 33 percent of organizations. And right at the top of that list is Apple iCloud.