For once, a serious question. How long should one of these 'spontaneous memorials' to be kept going (contd)?

If anything nasty happened to a relative or friend of mine I should want to bear that grief personally and privately and not publicise it for all to see just to prove how much it's hurting me. I know this is going to be very unpopular in a society where we are all now supposed to wear our hearts on our sleeves but personally I find those shrines undignified and tasteless.