Third rail electrification is less visually obtrusive than overhead electrification. The noise can be particularly obtrusive from some fluorescent light systems. The Africanis is well disposed without being obtrusive&colon; a friendly dog showing watchful territorial behaviour. It has aesthetic appeal; it provides a visualization of network traffic but without being obtrusive. Monorails are less obtrusive because they only require a single, narrow guidebeam. Floating ads may disappear or become less obtrusive after a pre-set time period. Enthusiasts say the seams were not obtrusive; detractors disagree. Because of the obtrusive mechanics behind this method, theatrical use was not practical. His earlier aggression towards the dysfunctions of an obtrusive system slowly turned into feigned support. This involved the removal of obtrusive galleries, and plaster from the internal walls. He was subject to constant and obtrusive supervision by the intelligence department. "The music won't be obtrusive," said Siegel.