It didn't take them long. Almost as soon as the lockdown restrictions started to lift, the anti-fish farm campaigners were back, crowding onto yachts without a thought for social distancing and setting off towards Scotland's salmon farms.
They then started on their usual antics, trying to climb on to pens, filming staff, diving underneath nets and sending drones up to grab video footage from the sky.
This is the pattern we have got used to and it is a pattern repeated the world over, not just around salmon farms but wherever farmers try to rear stock.
But there is a new and pressing dimension to these intrusions brought about by the Covid-19 crisis.
The number one duty of the Scottish Salmon Producers Organisation (SSPO) and its member companies is to look after the health and welfare of all those who work in our sector.
All our member companies stepped up as soon as the virus hit and all moved swiftly to make sure employee protection was paramount. Shift patterns were changed, transport options were extended, testing was offered, screens were installed and protective equipment was purchased.
Yet we now have activists, not just willing to break all Covid-related rules designed to protect the population, but apparently desperate to do so. They seem to think nothing of putting salmon farm employees in danger by clambering all over their places of work with no protective equipment and not a thought for whatever they might be bringing with them.
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As everyone who works in the sector knows, biosecurity is of crucial importance, not just on farms, but in hatcheries and in other sites too.
That is why visitors have to wear protective equipment, cleanse their footwear before venturing out and take great care.
This was an issue before Covid because of the health and welfare implications for the fish but it has now been multiplied because of the potential danger to staff working on these sites.
The activists who insist on invading these sites are showing a reckless disregard for the safety of themselves, of others and for the welfare of the fish - yet they seem either unaware of the dangers or they simply don't care.
This is a difficult area, not least because our rural police service is stretched and it takes time to react to the often swift interventions of some of more mobile critics.
But there are things we can do and the SSPO is starting an initiative which, we hope, will protect our employees from the very real stresses and potential dangers of having to deal with intruders in the future.
One of the keys to this is public support.
Our salmon farmers work in the marine environment. There are others who do this too: fishermen, energy workers, boat operators, tourist guides and others.
Then there are those who use the sea for recreation: like yachties, kayakers, divers and anglers.
We all have to share the marine environment. We all have to be good neighbours and careful custodians so we all have an interest in preventing a small group of militant activists from disrupting the balance we all need to work, co-exist and enjoy Scotland's coast.
Also, the law is quite clear. The rights of navigation allow journeys from any single point to another on the sea, except if there is a structure in the way (like a fish farm), in which case, the marine user has to go around the structure - not try to stop, tie up, clamber on board or dive underneath it.
The law against aggravated trespass on land (the Criminal Justice and Public Order Act of 1994) also covers a similar offence on marine structures.
But the key here is not legal strictures but consent. We are only going to dissaude this sort of threatening activity in the long run if we can get other marine users to recognise the dangers of intruders entering sites which are a danger to them and others.
We need every responsible marine user to act for all by notifying the authorities and acting as witnesses whenever there is illegal activity going on.
That is why the messages of safety and co-operation are the ones we have to stress above all others.
Salmon farms are potentially dangerous places. There are cables and pipes beneath the surface, ropes and other obstructions which can't be seen, feeding systems and other automated apparatus which can come on unexpectedly - and that is before the added perils of sea swells, currents, tides and waves are taken into account.
The SSPO and its members are preparing guidelines for marine users based on a 15m safety zone around all structures on our farms.
We will advise everybody using the sea to stay at least 15 metres from the edge of any structure, from all marker buoys and boats - for their safety and for ours.
At the same time, we will be putting out the clear message that we want people to see what we do, to find out what fish farming is all about and to understand what really goes on - but this has to be done properly, so that everyone (and all the livestock) are kept safe.
The SSPO had planned a major 'Open Farm Initiative' for early summer this year. The Covid crisis meant it didn't happen but we are keen to get it back on track again, as soon as we can.
That will show our commitment to openness, transparency and a desire to welcome all those who are interested to see what we do.
But the other side of that coin is respect for those who work on our farms, their health and safety and the welfare of the fish they grow.
Like death and taxes, these activists will always be with us. We cannot force them to disappear but what we can do is harness the consent of all the other, responsible, marine users to make it so difficult for them to invade our sites that they are kept right out on the fringes - which is where they should have been, all along.
This article by Hamish Macdonell, the SSPO's Director of Strategic Engagement, first appeared in Fish Farmer magazine.