Does Ripple slow down a user’s machine?

Ripple for the browser is very lightweight and causes no measurable resource  utilisation

If our IT systems already block harmful content, how does Ripple interact with this?

Browser Extension - Ripple for the browser compliments network level content filtering. Because it is  installed on the end point it can detect harmful web searches one step before network level equipment  can. There is no reason why the browser extensions cannot be used with a network filtering service at  the same time.