if a class contain just static methods as example i dont need to declare a CTOR, thats good.

extract from FxCop

Error, Certainty 90, for "StaticHolderTypesShouldNotHaveConstructors"
{
Target : "Indexus.AppCommon.TemporaryLogin" (IntrospectionTargetType)
Resolution : "Remove the public constructors from 'TemporaryLogin'.
"
Help : "http://www.gotdotnet.com/team/fxcop/docs/rules.aspx?version=1.312&&url=/Design/StaticHolderTypesShouldNotHaveConstructors.html" (String)
Category : "Microsoft.Design" (String)
CheckId : "CA1053" (String)
RuleFile : "Design Rules" (String)
Info : "Instances of types that define only static members
do not need to be created. Many compilers will automatically
add a public default constructor if no constructor
is specified. To prevent this, adding an empty private
constructor may be required."
Created : "2/26/2005 2:45:41 PM" (DateTime)
LastSeen : "2/26/2005 5:12:46 PM" (DateTime)
Status : Active (MessageStatus)
Fix Category : Breaking (FixCategories)
}