There was some sort of problem which caused the touch sensors to just go haywire. It was years ago now. The phone didn’t last terribly long for me.

It started bugging out in, initially, unpredictable ways. It would open and close apps almost at random, as well as interact with them, but only while or right after you were touching the screen. Sometimes it would freeze. Of course I restored the thing to factory settings, but it didn’t make a difference. It was unusable.