While this is traumatic on an individual level, and I would be pissed if I was one of these people, this doesn't seem like a huge deal to me. If there's intent behind it, it certainly does, but if it's simply an error, then it is an error that should be fixed hastily. If anything this could represent negligence and carlessness on the part of Coinbase, which would certainly be worse than an error.

If all is fixed up quick and in the end everything is refunded then there shouldn't be an issue.

There also is an option on Coinbase to set up repeating deposits into your account. Makes me wonder if it's human error rather than Coinbase error.