The HMRC and the DWP utilises a 80 million pound super computer with an algorithm to pick up red flags for tax evasion which is illegal and classified as fraud with prison time, the computer is called Connect and is Big Brother for a George Orwell themed dystopian and authoritarian regime and control from his book 1984, written in 1949.
Tax avoidance is perfectly legal as companies use it to save their tax bills.
The DWP uses social media to look for benefit claimants boasting by showing holiday photos of them water skiing in the Caribbean despite claiming for a bad back, immobility, being infirm or disabled.
The HMRC use covert officers and so do DWP fraud officers, they may lurk in public places such as a pub to over hear conversations of any unclaimed cash in hand jobs, sophisticated technology for recording evidence on covert operations and sound recording equipment.
For data intelligence they all use Companies House to see if anyone has property and unexplained wealth and assets, to run an Airbnb, B&B, or guest house.
The DVLA database to check for expensive cars, so owning a new Ferrari while claiming benefits could indicate a red flag.
Google Satellite Earth for a vehicle check or anything else they can snoop over.
For checking emails, text, and phone calls, their powers are limited, for a serious investigation they can dig a little bit deeper to see who the email went to, the date and time, the same for text, phone calls and voicemails.
Deleting any evidence is fruitless as the forensic team at the police can recover all deleted emails, calls, text and voicemails.
Using encryption can all be viewed by the forensic team.
Reports of fraud to the HMRC and DWP have high figures of jealous ex partners or a jealous neighbour to dob them in that turn out not to be fraud.