Some places require a valid E-Mail address and verification E-Mail response. If the verification E-Mail used tricks like vertically listed the valid numbers to verify your account, it is possible that automatic SPAM bots would fail. At least until they made changes…
I too have repetitive stress injury, just having flagged perhaps 30 posts, (about 1/2 were replies from the same SPAM bot). Though I did like watching them disappear from the latest posts list.