Instruct: Classify Amazon reviews into positive or negative sentiment
Query: It Leaks

I ordered these cups because my elderly mother frequently knocks over her drinks. They are nicely insulated and fit the hand well. However, when knocked over they leak. Granted, when they hit, only a couple of drops fly out. But if left on their side they seep liquid. It also takes a lot of effort to sip the drink. I am returning them because they are advertised to be 100% leak-proof and do not solve the problem of spilled beverages.