Years ago my credit score tanked to the mid 600s because they were reporting the limit on my cellphone plan as $70, so even though I had auto payment set up had never missed a payment in the 5 years I'd had the account, it was reporting as $60/70 utilized.

I was getting docked for "high utilization", even though the credit card that was connected to that account had a $25000 limit and was fully paid off every month.

3 months ago my mortgage showed up on my credit report, after not showing up for a year, and it dropped my score by 40 points until last week when it magically went back.

I'm in favour of the idea of credit reporting, there are a lot of people that abuse the system, and I think the lenders have a right to know if the person taking out a loan has a history of defaulting/missed payments or is carrying 6 figures of credit card debt, but assigning it a number seems so arbitrary.