I bought this lock http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWNX%3AIT

Then I found out that some of the old locks with the cylindrical keys can be opened with a bic pen... My U-lock uses a cylindrical key. And even if it can't be opened with a bic pen, I think someone can just use the keys from another U-lock and open my lock.

So how do I know if my u-lock is safe?