"He was charged under the Communications Act 2003, for sending malicious communications that were grossly offensive." So if he'd used a megaphone and said to their faces they wouldn't have been able to charge him? Crazy laws.
What I see here is the fact that it's written rather than verbal is how they got him. Does it make a difference to the offended families involved how the trolling was done? I bet not, it's just another example of how free-speech laws have diverged from today's technology.