4 VMs were scheduled to be deleted and there were horizon logs as below. But anyone didn't do that action. Is it possible that horizon terminates VMs without user action?

Thanks.

horizon_access.log

xx.xx.xx.xx - - [23/Apr/2015:00:59:48 +0000] "POST /admin/instances/ HTTP/1.1" 302 - "http://xx.xx.xx.xx/admin/instances/" "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.90 Safari/537.36"

horizon_error.log

400753:[Thu Apr 23 00:59:50.626984 2015] [:error] [pid 45080] REQ: curl -i 'http://xx.xx.xx.xx/v1.1/IaaS/servers/c2a3d3ba-577a-4a63-8860-7f67f4e6c667' -X DELETE -H "Accept: application/json" -H "User-Agent: python-novaclient" -H "X-Auth-Project-Id: IaaS" -H "X-Auth-Token: {SHA1}aadda77681abbfff61e4fdea9cf5a3281132de01"

400758:[Thu Apr 23 00:59:51.108233 2015] [:error] [pid 45080] REQ: curl -i 'http://xx.xx.xx.xx/v1.1/IaaS/servers/a2f8d4c9-34dc-47fa-ba1b-59c834b5e6d6' -X DELETE -H "Accept: application/json" -H "User-Agent: python-novaclient" -H "X-Auth-Project-Id: IaaS" -H "X-Auth-Token: {SHA1}aadda77681abbfff61e4fdea9cf5a3281132de01"

400763:[Thu Apr 23 00:59:51.683258 2015] [:error] [pid 45080] REQ: curl -i 'http://xx.xx.xx.xx/v1.1/IaaS/servers/e7c9ddb8-19e8-491a-908b-31f1070dca39' -X DELETE -H "Accept: application/json" -H "User-Agent: python-novaclient" -H "X-Auth-Project-Id: IaaS" -H "X-Auth-Token: {SHA1}aadda77681abbfff61e4fdea9cf5a3281132de01"

400768:[Thu Apr 23 00:59:52.180516 2015] [:error] [pid 45080] REQ: curl -i 'http://xx.xx.xx.xx/v1.1/IaaS/servers/78644498-400c-4ef5-bc9c-fc0b998c0b79' -X DELETE -H "Accept: application/json" -H "User-Agent: python-novaclient" -H "X-Auth-Project-Id: IaaS" -H "X-Auth-Token: {SHA1}aadda77681abbfff61e4fdea9cf5a3281132de01"