I went browsing thru my apps last night....and I decided to check out 'Messenger'. Boy was that a mistake! Once I clicked on the app it went into a 'login' screen and it INSISTED that I signup. I didn't WANT to signup, I just wanted to check out the app to see what it was all about. I use the word INSISTED because that's what the app continually did! I soon found out that using any/all 'back' buttons was FUTILE ! Yes,....it didn't matter what I did to try to back out of the app...it just kept INSISTING that I go ahead and signup...by going thru a continuing loop. I hit the 'back' button and the app seemed to shut down....and then BAM....it was right back...in my face...INSISTING that I signup ! What kind of BS is THAT Google??? I ended up having to do a complete SHUTDOWN of my Prime to deal with the problem! I've come to expect that kind of forceful/aggressive/Insistent behavior from that #@%$&*^&*# software company called Microsoft.....but I'm very disappointed and more than a little pissed off that Google now seems to be utilizing the same methodology under the guise of 'marketing'. Google,......THIS IS NOT GOOD ! I have put my trust in 'you' and I am a willing partner,....but THIS kind of behavior in your apps is unconscionable, uncalled for and unnecessary. If you want to continue to have a loyal following, then DON'T behave like MS! Please stop FORCING users to do things, and please make sure your marketing group is fully aware of this problem. Thanks Google for all the wonderful apps, and admirable corporate behavior up until now. Please review this app issue, AND your recent changes regarding users privacy. Singed, a Google loyalist and believer, as well as an avid and grateful Android user.