This might as well reach the IT yellow pages, but I stumbled upon an interesting situation noted in a thread on Google My Business Help. It seems that an SEO got pretty angry with Google for suspending 60 of his clients from the local maps listings a.k.a. Google My Business. This was actually his mistake since he was managing all these 60 clients from a single account.
The explanation for this action can be found at a Local Search Forum thread:
In general, if a single business gets picked up for spam, any other businesses owned by the same Google account can get suspended as well. For those of you working in bulk with many locations on the same account, there might be other rules there, I’d be interested to hear if that’s a danger for larger organizations as well.
This is proof that it is always better to have designated account for every client, especially if you have many. Basically, this is a real SEO mistake and his clients should not suffer from his wrong work ethics. Not to mention that this case is quite similar to the situation where you have spam accounts in a single Google Search Console account, which is a bad idea if you are, well, spamming.