What is the difference between intrusive and non-intrusive scans? 1) Intrusive scans require user permission, while non-intrusive scans do not. 2) Intrusive scans are more thorough than non-intrusive scans. 3) Intrusive scans can cause disruptions to the system being scanned, while non-intrusive scans do not. 4) Intrusive scans are faster than non-intrusive scans.