I'm a bit of a newbie, so I hope this isn't an already-answered question...
A URL of the form http://(item)/show/25 shows the 25th "item", but I've just noticed that http://(item)/show/25hello also displays this same item.
Q: is this a security concern, e.g. for SQL injection? Also, in the spirit of decreasing the temptation of hackers, is there a way to cause an error to be generated for such URLs, throughout a site?