Rolling out Copilot? Close these governance gaps first

A few weeks into most Copilot pilots, someone on the project team gets a message along the lines of “should I be able to see this?” Usually it’s a salary spreadsheet or a board paper, and it came back as part of a perfectly ordinary Copilot answer. 

Nothing has been breached. Copilot only works with content the person asking is already allowed to open. What it removes is the obscurity that was hiding years of governance shortcuts. 

If this has slowed your rollout, you’re in good company. In Gartner’s 2024 survey, 40% of IT leaders delayed Copilot by three months or more because of oversharing concerns [1]. CoreView’s 2026 research found 66% of organisations had paused or cancelled a rollout, and 73% of those cited the risk of AI surfacing confidential information [2]. At Gartner’s Sydney conference in May 2025, analysts named oversharing and content sprawl among the challenges keeping organisations at the pilot stage [3]. 

The good news is that these are known problems with known fixes. Roll Copilot out before dealing with them, and these are the gaps it tends to find. 

Six governance gaps Copilot exposes 

• Sites open to everyone. The “Everyone except external users” group was added once to make a link work. Now any employee’s prompt can draw on that HR or finance library. Varonis found organisations had more than 25,000 sensitive folders open to every employee, on average.
• Sharing links that never expire. Organisation-wide links made for a one-off job still work years later, long after anyone remembers who they were sent to. 
• Sites with no owner. When the owner has left the business, nobody reviews who has access, so nothing gets tightened. 
• Sensitive content with no label. Without sensitivity labels, neither Copilot nor your DLP policies can tell a redundancy list from a morning tea roster. Only 1 in 10 organisations in the same Varonis study had labelled files [4]. 
• Old content that was never cleaned up. With no retention in place, Copilot answers as confidently from a superseded policy as from the current one. 
• No view of how AI is being used. Without monitoring, nobody knows what staff are pasting into prompts or what comes back. Microsoft’s Work Trend Index found 78% of AI users bring their own AI tools to work, and 52% are reluctant to admit using AI for their most important tasks [6]. 

Microsoft tools to find and contain Copilot oversharing 

See the problem with DSPM 

Start by getting a proper look at the problem. Data Security Posture Management in Microsoft Purview (DSPM for AI is now part of it) automatically runs a weekly data risk assessment across your 100 most-used SharePoint sites [7]. It shows where sensitive content is broadly shared. Results take about four days to appear the first time, so open it early [8]. 

Add guardrails with DLP for Copilot 

While the clean-up is under way, DLP for Microsoft 365 Copilot gives you some guardrails. It can stop Copilot responding when a prompt contains things like tax file numbers or credit card numbers, and it can stop Copilot summarising files that carry your most sensitive labels. Microsoft’s default policy starts in simulation mode, which logs matches without blocking them [9]. 

Two limits are worth knowing. DLP only checks what’s typed into the prompt, not files uploaded with it, and Microsoft still lists prompt blocking as a preview feature, so check it has reached your tenant [10]. 

Move from Restricted SharePoint Search to Restricted Content Discovery 

Restricted SharePoint Search was the quick fix in a lot of early rollouts, but Microsoft is retiring it. New enablement has been blocked since 31 July 2026, and it stops working entirely on 31 January 2027 [11][12]. Microsoft won’t migrate existing settings, so plan the move now [12]. 

Its replacement is Restricted Content Discovery, which hides individual sites from Copilot and organisation-wide search without touching permissions [13]. Think of it as breathing room while you fix the access underneath. 

A 90-day Copilot governance plan 

Days 1 to 30: find it and contain it 

Run the DSPM assessment and the sharing reports in SharePoint Advanced Management. List the sites you’d least like to see in a Copilot answer (HR, finance, legal and the executive team) and put Restricted Content Discovery on them. Set up DLP for Copilot in simulation mode. 

Days 31 to 60: fix what you found 

Send access reviews to site owners and find new owners for orphaned sites. Remove company-wide groups and old sharing links, and change the default sharing link to “specific people”. Publish a small set of sensitivity labels, put retention on content nobody has touched in years, then switch the DLP rules from simulation to enforcement. 

Days 61 to 90: make it routine 

Lift the restrictions as each site is signed off. Check the assessment and Copilot activity every week, and give the executive team a few numbers to track, so the tenant doesn’t drift back to where it started. 

Copilot works better on a well-governed tenant 

None of this is new work. Permission reviews, labelling and site ownership have sat on most IT teams’ to-do lists for years, and Copilot is finally the reason to do them. It also gives better answers once the clean-up is done. 

Planning a rollout, or already getting those “should I be able to see this?” messages? Talk to Oreta about a Copilot readiness assessment of your tenant. Book a conversation. 

Frequently asked questions 

Can Microsoft 365 Copilot show people files they can’t access? No. Copilot only uses content the person asking already has permission to open. It makes overshared content easier to find, which is why permissions need reviewing first. 

What is Copilot oversharing? It’s when Copilot surfaces sensitive content, such as salaries or board papers, to staff who technically have access through broad permissions or old sharing links, but were never meant to see it. 

How do I find overshared content before rolling out Copilot? Start with the data risk assessment in Microsoft Purview DSPM, which runs weekly across your 100 most-used SharePoint sites, and the sharing reports in SharePoint Advanced Management. 

Is Restricted SharePoint Search still available? No for new setups. New enablement was blocked from 31 July 2026, and it retires fully on 31 January 2027. Restricted Content Discovery is Microsoft’s recommended replacement. 

How long does Copilot governance readiness take? A focused programme can find, fix and embed the essentials in about 90 days: contain the riskiest sites first, remediate access and labelling next, then make reviews routine. 

References 

1. Computerworld, Microsoft 365 Copilot rollouts slowed by data security, ROI concerns (Gartner survey of 132 IT leaders), 2024. 
2. Infosecurity Magazine, Microsoft Copilot Deployments Delayed Over Security Concerns (CoreView State of Microsoft 365 Security and Governance 2026), July 2026. 
3. techpartner.news, Gartner: Microsoft Copilot hype offset by ROI and readiness realities, 2025. 
4. Varonis, 2025 State of Data Security Report: Quantifying AI’s Impact on Data Risk. 
5. CPA British Columbia, Proactive Steps Needed to Mitigate AI’s Impact on Data Security (summary of the Varonis report), January 2026. 
6. Microsoft WorkLab, 2024 Work Trend Index: AI at Work Is Here. Now Comes the Hard Part. 
7. Microsoft Learn, Learn about Data Security Posture Management (DSPM) for AI. 
8. Microsoft Learn, Data risk assessments for oversharing in DSPM. 
9. Microsoft Learn, Default DLP policy for the Microsoft 365 Copilot location. 
10. Atlan, Purview controls for AI agents (citing Microsoft Learn, updated 17 September 2026). 
11. Microsoft Learn, Restricted SharePoint Search. 
12. Microsoft 365 Message Center, MC1395311: Retirement of Restricted SharePoint Search, June 2026. 
13. Microsoft Learn, Govern SharePoint and OneDrive for Copilot: choose the right control.