Recent movement in the pub trade, with mergers, acquisitions and disposals, has led to an increased trade for security companies that patrol empty buildings.
"Because of the increasing amount of pubs up for disposal, business is booming," said Steph Hunter, from security firm Vacant Property Security (VPS).
"Pub companies merging, acquisitions and all the changes in the trade mean companies need us. While they're moving their stock or waiting for new tenants, they call on us to make the empty pub secure."
VPS, which does a lot of work for East Anglia-based pub operator Greene King, makes closed-down pubs safe from vandals, squatters and so on by fixing steel window panels and door screens to the building.
Ms Hunter said it was vitally important for empty pubs to be made secure because a pub is, after all, a pub operator's most valuable asset.
High levels of theft from pub sites which are being refurbished and incidents of vandalism are a real threat when a pub is closed, according to VPS.
And a new weight of responsibility - for the health and safety of any contractors working on site - now lies with the pubco.
VPS founder David White explained: "It is a fact that a well-secured property will not only keep people out, it also keeps workers in and in the case of an accidental fire preventing escape through the single open exit, this form of security could prove to be a lethal trap."
He said it was important that pub companies realised this risk and, when securing their empty outlets, made sure there were sufficient emergency exits for contractors - a European law on health and safety issues also states as much.
"When seatbelts didn't exist, no one demanded them - now a whole new weight of legal responsibility rests on your shoulders if you don't use them," Mr White said.
Causing unnecessary damage to an empty property is something else pub operators should be careful to avoid.
The traditional method of boarding up windows and doors often causes a large amount of damage to wooden window frames as well as PVC frames and seals on double glazing.
When choosing how to secure a pub, VPS advises the trade to look at new technology rather than old methods - which are also unsightly and not particularly secure.
For more information contact VPS on 020 8695 6611 or visit www.vacantpropertysecurity.com.