It happens.. more than you think, and we don’t care unless you give us a reason to. The rule of thumb here is, do we need an excuse to look in to your Internet and office PC usage?
We only care if it is illegal or causing issues on the network like bandwidth hogging. Most companies will have a firewall and block anything malicious or sites employees should not be visiting.
If you are using your own device, like a mobile phone or laptop, that does not have any work software on it, then the most we can see is the website you are accessing (for example, www.google.com).
If you are using a work device, such as a work mobile phone or work/school laptop, then expect us to be able to see everything, including any encrypted (HTTPS) websites. Your device will probably be controlled by software that gives us full access to everything you are doing on it.