Indeed it can be.
Supporting your point, I cut this Gem from Motorcycle Cruiser Magazine:
http://www.motorcyclecruiser.com/streetsurvival/group_motorcycle_safety/index.html
The basic group riding formation is familiar to most riders. The lead rider rides to the left of the lane, with the second rider to the right and a few lengths back. The third rider is a similar distance behind the second, and so on. This staggered formation leaves room for each bike to swerve to the side and provides reaction time to brake. But you can't change speed and the side of the lane at the same time. Riding side by side limits escape routes when a threat arises. When overtaking and passing traffic, the second rider follows the first, and the third hangs back to let the second pull in to the left to make the pass.
When roads get twisty or narrow, you should open up into a single-file formation. When you come to a stop at an intersection, tighten up into a two-abreast configuration at the stop. If you all stay in a single lane at intersections with two or more lanes each way, it gives the traffic behind you a chance to pass. While it is tempting to block an intersection so your entire group can go through, it is against the law. So is going leaving in large bunches at a time from a four-way stop. More than two (you can each say you thought the other was waiting) is also a request for citation.
One common problem I see with large groups is a failure to provide gaps for other traffic. On a two-lane road, it may be impossible for overtaking traffic to safely pass a line of a dozen or more motorcycles. Some members of the group may get run off the road if a driver tries to pass and has to pull back into the right lane when oncoming traffic appears. On a multi-lane road like an interstate, a long double column of motorcycles may trap a car on one side of it, blocking it from reaching an exit. Some riders act as if permitting a car to cross their column of bikes is a violation of their religious and constitutional rights, and can make a driver already in a panic about missing his exit quite dangerous.
Do address this problem. It's best to ride in sub-groups of four to six bikes and provide a gap of four or more car lengths between each sub-group. These groups can also be responsible for each other, taking care of other members of their group so that the entire fleet of bikes doesn't end up trying to squeeze onto the shoulder, which can create a real hazard.