When I get to the top of my local A, or to the parking lot of a local E, or the exit point on a S (you get the picture...), and I find a BASE sticker (or ANY sticker, for that matter) It raises my blood pressure a good 50 points.
The locals in my area, as I'm sure in most other areas, work hard to preserve our sites and keep BASE jumpers from run ins with law enforcement. We do this by practicing the "leave no trace" rules...they're pretty simple--make it look like you were never there. It's not just cops that you want to avoid; it's ANY contact or detection by ANYONE. Litter, stickers, and in some cases even footprints or tire tracks are unacceptable (hmmmm...why are there two muddy footprints on the top of this tower?).
Sure I know your crew or team or friend or whatever made these cool stickers and you want the world to see them, but a BASE site, LEGAL OR NOT is not the right place for this kind of thing.
Please be courteous when visiting another area, don't put your cool stickers on BASE objects. IMHO, This sort of thing is akin to site burning.