There's an unwritten rule in business that says companies should never mention their competitors because it gives them unwanted publicity. Blackberry's CEO, John Chen, just did that by pointing to Google's security announcement from Google IO 2014 last month.

In a rather odd slide, he commented on the Google's decision to adopt Samsung KNOX for the next generation of Android, called L, saying that while they applauded the plans, they didn't think it was enough for security-minded enterprises.

Instead, Chen encourages us to look to technology companies that have invested 30 years in advancing security and productivity, and one that, in particular, has "proven repeatedly it can walk the walk". No prizes for guessing who that is.

Why Chen chose to do what is a PR exercise when Google IO 2014 has faded is unclear but it is interesting to see that Blackberry considers Android to be a competitor to be reckoned with.

Both companies have had a love-hate history. Blackberry launched its popular BBM for Android and opened up its Blackberry OS platform to run native Android apps.