Do these little speed bumps even work? I have to admit I'm so numb to all these popups and to apps warning me this and begging me that, that I just don't read anything anymore. Each app that hits me up with yet another dialog is just another brick in the wall.
The only speed bump that I find super annoying is when your browser tries to prevent you from going to a site with an incorrectly configured certificate (or a self signed certificate). The UX browsers make you navigate in this case is extra-horrible. Apparently, my use of a self-signed certificate for some local machines means I'm about to die.
We recently rolled over an SSL cert that is used for RemoteApps. Most of my users rely on these RemoteApps. They all got the 'yellow warning box' that the SSL cert was different, and we got swamped with tickets.
Atleast in a corporate environment, they help
I have been using the internet since before the www. In the last few years I pay attention to every speed bump and evaluate it seriously. I check the url of every financial site I log into. I disable automatic security blocks as a last resort. There's just too much consequence for failure.