Leosghost - 11:59 pm on Mar 16, 2011 (gmt 0)
That would be an incorrect assumption to make on the basis of the replies you have so far, and there have been other threads here in the past dealing with more or less the same question..
You appear to be confusing "liability" ( a legal term ) with protecting your adsense income by having multiple legal corporate entities ( LLC's in your home jurisdiction )in case Google should decide to close your adsense account which apparently is registered to your current ( sole ) LLC ?
If you are worried about what Google might think or do in relation to one or more of your sites ..then only you can decide what the risk is ..and if it is worth your while setting up multiple LLC's as in one per site.
Some people own more than one company ..some don't ..depends on the individual and their circumstances.