Can BIG acro crabs be a problem?

[iamwhatiam52]

I have an acro crab ( at least it acts like an acro crab) that has grown to 3/4 inch carapace. It has caused no problems, and there is even a pair of black clown gobies nesting an inch away.

How big can they get?

Is there danger of larger ones becoming predatory?

 

[kar93]

picture would help