And inside the republican community there is nothing worse you can be accused of.
This time, it was aimed at former IRA figures who recorded tapes for the Boston College oral history project.
And it was deliberately written in several places where it would be seen and read. The graffiti was an expression of building anger.
Brendan Hughes, once part of the IRA's so-called 'D' Company in the lower Falls and its 2nd battalion stretching from Divis Street to the Whiterock, is one of those who on the Boston tapes implicated the Sinn Fein president in the Jean McConville killing.
Hughes, now dead, alleged it was Adams who gave the order to disappear the widowed mother-of-10 – something the Sinn Fein leader has repeatedly denied.
But that allegation, alongside claims made on other Boston tapes by former IRA figures, formed a substantial part of this police investigation and the questioning of the Louth TD and former West Belfast MP.
There was also what was described as "open source" material printed in books and newspapers and reading back over several decades.
This included Adams' own book Before The Dawn.
Police are also known to have sought witness statements from others who made allegations about Adams in recent media interviews.
Those requests were declined. But the interviewing approach indicated that this questioning of Adams was in a much wider frame than just the abduction, killing and disappearing of Mrs McConville.
Within hours of the Sinn Fein leader's arrest, some republicans believed the police were attempting to construct an IRA membership charge. Several decades ago, a similar charge failed.
The appearance of that graffiti in parts of west Belfast coincided with Saturday's protest rally and unveiling of a new Gerry Adams mural. That gathering was designed as both a show of strength and a show of support.
Martin McGuinness and Martina Anderson were on the stage with Bobby Storey – one of the most senior figures from the IRA's 'war' years. He is big in republican stature and rank.
Among the crowd were Adams' brother Paddy and Eibhlin Glenholmes, who spent years on the run and who was once described under the banner headline Britain's Most Wanted.
Martin Lynch, Padraic Wilson and Jim McVeigh – all with past IRA credentials – were present. And so too Adams' aide Richard McAuley, Policing Board members Gerry Kelly and Pat Sheehan, the local MP Paul Maskey and ministers Caral Ni Chuilin and Jennifer McCann.
Borrowing Adams' words from a different time and a different place, Storey shouted out Sinn Fein's message to the British and Irish Governments.
To loud applause and cheers, he said: "We ain't going away you know."
But republicans know something else isn't going away – the questions that relate to that ugly chapter of the Disappeared.
Through their families, they have spoken. Not all of the bodies have been found – and this issue of the Disappeared is part of an incomplete peace. An incomplete peace that at some time is going to need some type of process. And this is part of what angered republicans.
Before that process was agreed and shaped, Adams was arrested, held and questioned.
So, in all of this there will be ramifications – policing and political.